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The Diagnosis: Cutaneous Tuberculosis 

The patient's medical history was notable for bone tuberculosis (TB) treated in childhood. Skin biopsy revealed neutrophilic infiltrates with necrosis without granulomas. A real-time polymerase chain reaction test detected Mycobacterium tuberculosis complex in the skin fragment, which was confirmed by culture of the biopsy specimen using a liquid growth medium that grew M tuberculosis. Tuberculotic foci were not present on the lungs, gastrointestinal tract, kidneys, and bones by radiologic, microbiologic, and ultrasonographic investigations. The patient was started on 4 antituberculotic drugs--isoniazid 300 mg, rifampicin 600 mg, ethambutol 1200 mg, pyrazinamide 1500 mg--once daily for 2 months followed by isoniazid 300 mg and rifampicin 600 mg once daily for another 4 months with resolution of the skin lesions. 

Cutaneous TB is an infectious disease caused by M tuberculosis and accounts for only 1.5% of extrapulmonary TB cases.^1,2 Similar to other forms of TB, a resurgence of cutaneous TB has been noted in parts of the world where human immunodeficiency virus infection is prevalent and remains to be one of the most elusive and more difficult diseases to diagnose.³ Thought to be a predominantly occupational disease, it is being encountered more frequently in healthy individuals where the source of infection remains unidentified in most cases.⁴ The clinical types depend on the method of infection, virulence of the bacillus, immune status of the host, and presence or absence of host sensitization to M tuberculosis.² The route of infection is used to classify cutaneous mycobacteriosis.⁵ Inoculation from an exogenous source can produce TB verrucosa cutis in individuals who have previously been sensitized to M tuberculosis or tuberculous chancre in individuals without prior exposure to the bacterium.⁴ Cutaneous TB resulting from direct spread to the skin from an underlying contiguous structure in most cases spreads from lymph nodes and bone (scrofuloderma). Immunosuppressed patients with advanced TB of the lung, gastrointestinal tract, or the genitourinary tract may present with periorificial TB.⁴ Dissemination to the skin caused by hematogenous spread can occur in the form of lupus vulgaris, miliary TB, or metastatic tuberculous abscesses (gummas).^4,5 A fourth category--cutaneous TB from paradoxical expansion--also was proposed. Paradoxical expansion is defined as the transient expansion of a preexisting lesion or the appearance of new lesions during appropriate anti-TB therapy.⁵ 

Although histopathology and protein chain reaction tests are useful, the gold standard for diagnosis is still the isolation of M tuberculosis on culture.^3,6 Treatment regimens of cutaneous TB are similar to those of pulmonary TB, with a 4-agent regimen given for 2 months followed by a 2-drug regimen for the next 4 months.^1,7 The differential diagnosis of leg ulcers includes stasis ulcer, necrobiotic xanthogranuloma, pyoderma gangrenosum, and squamous cell carcinoma, among others. Cutaneous biopsy, microbiological culture, and a high degree of suspicion are fundamental for the final diagnosis. Cutaneous TB should be suspected in immunocompetent as well as in immunosuppressed patients who present with ulcerated lesions that do not respond to antibacterial treatment.

The Diagnosis: Cutaneous Tuberculosis 

The patient's medical history was notable for bone tuberculosis (TB) treated in childhood. Skin biopsy revealed neutrophilic infiltrates with necrosis without granulomas. A real-time polymerase chain reaction test detected Mycobacterium tuberculosis complex in the skin fragment, which was confirmed by culture of the biopsy specimen using a liquid growth medium that grew M tuberculosis. Tuberculotic foci were not present on the lungs, gastrointestinal tract, kidneys, and bones by radiologic, microbiologic, and ultrasonographic investigations. The patient was started on 4 antituberculotic drugs--isoniazid 300 mg, rifampicin 600 mg, ethambutol 1200 mg, pyrazinamide 1500 mg--once daily for 2 months followed by isoniazid 300 mg and rifampicin 600 mg once daily for another 4 months with resolution of the skin lesions. 

Cutaneous TB is an infectious disease caused by M tuberculosis and accounts for only 1.5% of extrapulmonary TB cases.^1,2 Similar to other forms of TB, a resurgence of cutaneous TB has been noted in parts of the world where human immunodeficiency virus infection is prevalent and remains to be one of the most elusive and more difficult diseases to diagnose.³ Thought to be a predominantly occupational disease, it is being encountered more frequently in healthy individuals where the source of infection remains unidentified in most cases.⁴ The clinical types depend on the method of infection, virulence of the bacillus, immune status of the host, and presence or absence of host sensitization to M tuberculosis.² The route of infection is used to classify cutaneous mycobacteriosis.⁵ Inoculation from an exogenous source can produce TB verrucosa cutis in individuals who have previously been sensitized to M tuberculosis or tuberculous chancre in individuals without prior exposure to the bacterium.⁴ Cutaneous TB resulting from direct spread to the skin from an underlying contiguous structure in most cases spreads from lymph nodes and bone (scrofuloderma). Immunosuppressed patients with advanced TB of the lung, gastrointestinal tract, or the genitourinary tract may present with periorificial TB.⁴ Dissemination to the skin caused by hematogenous spread can occur in the form of lupus vulgaris, miliary TB, or metastatic tuberculous abscesses (gummas).^4,5 A fourth category--cutaneous TB from paradoxical expansion--also was proposed. Paradoxical expansion is defined as the transient expansion of a preexisting lesion or the appearance of new lesions during appropriate anti-TB therapy.⁵ 

Although histopathology and protein chain reaction tests are useful, the gold standard for diagnosis is still the isolation of M tuberculosis on culture.^3,6 Treatment regimens of cutaneous TB are similar to those of pulmonary TB, with a 4-agent regimen given for 2 months followed by a 2-drug regimen for the next 4 months.^1,7 The differential diagnosis of leg ulcers includes stasis ulcer, necrobiotic xanthogranuloma, pyoderma gangrenosum, and squamous cell carcinoma, among others. Cutaneous biopsy, microbiological culture, and a high degree of suspicion are fundamental for the final diagnosis. Cutaneous TB should be suspected in immunocompetent as well as in immunosuppressed patients who present with ulcerated lesions that do not respond to antibacterial treatment.

The Diagnosis: Cutaneous Tuberculosis 

The patient's medical history was notable for bone tuberculosis (TB) treated in childhood. Skin biopsy revealed neutrophilic infiltrates with necrosis without granulomas. A real-time polymerase chain reaction test detected Mycobacterium tuberculosis complex in the skin fragment, which was confirmed by culture of the biopsy specimen using a liquid growth medium that grew M tuberculosis. Tuberculotic foci were not present on the lungs, gastrointestinal tract, kidneys, and bones by radiologic, microbiologic, and ultrasonographic investigations. The patient was started on 4 antituberculotic drugs--isoniazid 300 mg, rifampicin 600 mg, ethambutol 1200 mg, pyrazinamide 1500 mg--once daily for 2 months followed by isoniazid 300 mg and rifampicin 600 mg once daily for another 4 months with resolution of the skin lesions. 

Cutaneous TB is an infectious disease caused by M tuberculosis and accounts for only 1.5% of extrapulmonary TB cases.^1,2 Similar to other forms of TB, a resurgence of cutaneous TB has been noted in parts of the world where human immunodeficiency virus infection is prevalent and remains to be one of the most elusive and more difficult diseases to diagnose.³ Thought to be a predominantly occupational disease, it is being encountered more frequently in healthy individuals where the source of infection remains unidentified in most cases.⁴ The clinical types depend on the method of infection, virulence of the bacillus, immune status of the host, and presence or absence of host sensitization to M tuberculosis.² The route of infection is used to classify cutaneous mycobacteriosis.⁵ Inoculation from an exogenous source can produce TB verrucosa cutis in individuals who have previously been sensitized to M tuberculosis or tuberculous chancre in individuals without prior exposure to the bacterium.⁴ Cutaneous TB resulting from direct spread to the skin from an underlying contiguous structure in most cases spreads from lymph nodes and bone (scrofuloderma). Immunosuppressed patients with advanced TB of the lung, gastrointestinal tract, or the genitourinary tract may present with periorificial TB.⁴ Dissemination to the skin caused by hematogenous spread can occur in the form of lupus vulgaris, miliary TB, or metastatic tuberculous abscesses (gummas).^4,5 A fourth category--cutaneous TB from paradoxical expansion--also was proposed. Paradoxical expansion is defined as the transient expansion of a preexisting lesion or the appearance of new lesions during appropriate anti-TB therapy.⁵ 

Although histopathology and protein chain reaction tests are useful, the gold standard for diagnosis is still the isolation of M tuberculosis on culture.^3,6 Treatment regimens of cutaneous TB are similar to those of pulmonary TB, with a 4-agent regimen given for 2 months followed by a 2-drug regimen for the next 4 months.^1,7 The differential diagnosis of leg ulcers includes stasis ulcer, necrobiotic xanthogranuloma, pyoderma gangrenosum, and squamous cell carcinoma, among others. Cutaneous biopsy, microbiological culture, and a high degree of suspicion are fundamental for the final diagnosis. Cutaneous TB should be suspected in immunocompetent as well as in immunosuppressed patients who present with ulcerated lesions that do not respond to antibacterial treatment.

The Diagnosis: Fracture Blisters 

The shave biopsy pathology demonstrated a subepidermal bulla with re-epithelialization that was clinically consistent with fracture blisters (also known as fracture bullae)(Figure). Fracture blisters are a complication of bone fractures, usually occurring 24 to 48 hours after the trauma but possibly up to 3 weeks later. The skin usually is edematous with tense bullae overlying the fracture (in this case it was distal to the fracture); most blisters contain clear fluid, but older blisters tend to be more flaccid with hemorrhagic fluid.¹ The cause is thought to be the result of skin strain during fracture formation.² Edema and hypoxia from injured vessels and lymphatics contribute to the formation of bullae, which are seen as a dermoepidermal junction split on histology.¹ 

The bullae are histologically indistinguishable from edema blisters. A clinical history can help to differentiate. Edema blisters occur in the setting of an acute exacerbation of chronic edema, usually on the lower extremities in the setting of fluid overload.³ Bullous cellulitis is associated with skin erythema, warmth, and systemic symptoms. Bullous pemphigoid can be localized to the lower legs at times; however, biopsy would show a subepidermal bulla with eosinophils along the dermoepidermal junction. Linear IgA bullous dermatosis can be drug induced from vancomycin; however, pathology would show a subepidermal blister with a neutrophil predominant infiltrate. Nonsteroidal anti-inflammatory medications such as naproxen are a common culprit for bullous drug eruptions, which can be localized or generalized and include diagnoses such as fixed drug eruption, toxic epidermal necrolysis, and drug-induced pseudoporphyria. Naproxen-induced pseudoporphyria more commonly presents with blisters, erosions, and scarring with a predilection for the dorsal hands. Histology also will demonstrate subepidermal bullae. Clues to differentiate pseudoporphyria from fracture blisters include festooning of the dermal papilla and caterpillar bodies consisting of basement membrane material and colloid bodies in the basal layer of the epidermis, though they are not always present.⁴ 

Fracture blisters can be localized to the injury site or extend beyond the fracture site. They usually are found where there is minimal subcutaneous tissue, such as the tibia, ankles, and elbows. Fractures treated within 24 hours are much less likely to have bullae formation.¹ The bullae are sterile but may lead to wound healing complications, such as infections or delay in surgical management. However, there are no major adverse effects of postoperative fracture blisters.¹ Fracture blisters are self-healing, though silver sulfadiazine has been shown to minimize soft-tissue complications by promoting re-epithelialization.⁵ 
 

The Diagnosis: Fracture Blisters 

The shave biopsy pathology demonstrated a subepidermal bulla with re-epithelialization that was clinically consistent with fracture blisters (also known as fracture bullae)(Figure). Fracture blisters are a complication of bone fractures, usually occurring 24 to 48 hours after the trauma but possibly up to 3 weeks later. The skin usually is edematous with tense bullae overlying the fracture (in this case it was distal to the fracture); most blisters contain clear fluid, but older blisters tend to be more flaccid with hemorrhagic fluid.¹ The cause is thought to be the result of skin strain during fracture formation.² Edema and hypoxia from injured vessels and lymphatics contribute to the formation of bullae, which are seen as a dermoepidermal junction split on histology.¹ 

The bullae are histologically indistinguishable from edema blisters. A clinical history can help to differentiate. Edema blisters occur in the setting of an acute exacerbation of chronic edema, usually on the lower extremities in the setting of fluid overload.³ Bullous cellulitis is associated with skin erythema, warmth, and systemic symptoms. Bullous pemphigoid can be localized to the lower legs at times; however, biopsy would show a subepidermal bulla with eosinophils along the dermoepidermal junction. Linear IgA bullous dermatosis can be drug induced from vancomycin; however, pathology would show a subepidermal blister with a neutrophil predominant infiltrate. Nonsteroidal anti-inflammatory medications such as naproxen are a common culprit for bullous drug eruptions, which can be localized or generalized and include diagnoses such as fixed drug eruption, toxic epidermal necrolysis, and drug-induced pseudoporphyria. Naproxen-induced pseudoporphyria more commonly presents with blisters, erosions, and scarring with a predilection for the dorsal hands. Histology also will demonstrate subepidermal bullae. Clues to differentiate pseudoporphyria from fracture blisters include festooning of the dermal papilla and caterpillar bodies consisting of basement membrane material and colloid bodies in the basal layer of the epidermis, though they are not always present.⁴ 

Fracture blisters can be localized to the injury site or extend beyond the fracture site. They usually are found where there is minimal subcutaneous tissue, such as the tibia, ankles, and elbows. Fractures treated within 24 hours are much less likely to have bullae formation.¹ The bullae are sterile but may lead to wound healing complications, such as infections or delay in surgical management. However, there are no major adverse effects of postoperative fracture blisters.¹ Fracture blisters are self-healing, though silver sulfadiazine has been shown to minimize soft-tissue complications by promoting re-epithelialization.⁵ 
 

The Diagnosis: Fracture Blisters 

The shave biopsy pathology demonstrated a subepidermal bulla with re-epithelialization that was clinically consistent with fracture blisters (also known as fracture bullae)(Figure). Fracture blisters are a complication of bone fractures, usually occurring 24 to 48 hours after the trauma but possibly up to 3 weeks later. The skin usually is edematous with tense bullae overlying the fracture (in this case it was distal to the fracture); most blisters contain clear fluid, but older blisters tend to be more flaccid with hemorrhagic fluid.¹ The cause is thought to be the result of skin strain during fracture formation.² Edema and hypoxia from injured vessels and lymphatics contribute to the formation of bullae, which are seen as a dermoepidermal junction split on histology.¹ 

The bullae are histologically indistinguishable from edema blisters. A clinical history can help to differentiate. Edema blisters occur in the setting of an acute exacerbation of chronic edema, usually on the lower extremities in the setting of fluid overload.³ Bullous cellulitis is associated with skin erythema, warmth, and systemic symptoms. Bullous pemphigoid can be localized to the lower legs at times; however, biopsy would show a subepidermal bulla with eosinophils along the dermoepidermal junction. Linear IgA bullous dermatosis can be drug induced from vancomycin; however, pathology would show a subepidermal blister with a neutrophil predominant infiltrate. Nonsteroidal anti-inflammatory medications such as naproxen are a common culprit for bullous drug eruptions, which can be localized or generalized and include diagnoses such as fixed drug eruption, toxic epidermal necrolysis, and drug-induced pseudoporphyria. Naproxen-induced pseudoporphyria more commonly presents with blisters, erosions, and scarring with a predilection for the dorsal hands. Histology also will demonstrate subepidermal bullae. Clues to differentiate pseudoporphyria from fracture blisters include festooning of the dermal papilla and caterpillar bodies consisting of basement membrane material and colloid bodies in the basal layer of the epidermis, though they are not always present.⁴ 

Fracture blisters can be localized to the injury site or extend beyond the fracture site. They usually are found where there is minimal subcutaneous tissue, such as the tibia, ankles, and elbows. Fractures treated within 24 hours are much less likely to have bullae formation.¹ The bullae are sterile but may lead to wound healing complications, such as infections or delay in surgical management. However, there are no major adverse effects of postoperative fracture blisters.¹ Fracture blisters are self-healing, though silver sulfadiazine has been shown to minimize soft-tissue complications by promoting re-epithelialization.⁵ 
 

The Diagnosis: Bleomycin-Induced Flagellate Hyperpigmentation 

Histopathology of the affected skin demonstrated a slight increase in collagen bundle thickness, a chronic dermal perivascular inflammation, and associated pigment incontinence with dermal melanophages compared to unaffected skin (Figure). CD34 was faintly decreased, and dermal mucin increased in affected skin. This postinflammatory pigmentary alteration with subtle dermal sclerosis had persisted unchanged for more than 5 years after cessation of bleomycin therapy. Topical hydroquinone, physical blocker photoprotection, and laser modalities such as the Q-switched alexandrite (755-nm)/Nd:YAG (1064-nm) and ablative CO₂ resurfacing lasers were attempted with minimal overall impact on cosmesis. 

Bleomycin is a chemotherapeutic antibiotic that has been commonly used to treat Hodgkin lymphoma, germ cell tumors, and recurrent malignant pleural effusions.¹ The drug is inactivated in most tissues by the enzyme bleomycin hydrolase. This enzyme is not present in skin and lung tissue; as a result, these organs are the most common sites of bleomycin toxicity.¹ There are a variety of cutaneous effects associated with bleomycin including alopecia, hyperpigmentation, acral erythema, Raynaud phenomenon, and nail dystrophy.² Flagellate hyperpigmentation is a less common cutaneous toxicity. It is an unusual eruption that appears as whiplike linear streaks on the upper chest and back, limbs, and flanks.³ This cutaneous manifestation was once thought to be specific to bleomycin use; however, it also has been described in dermatomyositis, adult-onset Still disease, and after the ingestion of uncooked or undercooked shiitake mushrooms.⁴ Flagellate hyperpigmentation also was once thought to be dose dependent; however, it has been described in even very small doses.⁵ The eruption has been described as independent of the route of drug administration, appearing with intravenous, subcutaneous, and intramuscular bleomycin.² The association of bleomycin and flagellate hyperpigmentation has been reported since 1970; however, it is less commonly seen in clinical practice with the declining use of bleomycin.¹  

The exact mechanism for the hyperpigmentation is unknown. It has been proposed that the linear lesions are related to areas of pruritus and subsequent excoriations.¹ Dermatographism may be present to a limited extent, but it is unlikely to be a chief cause of flagellate hyperpigmentation, as linear streaks have been reported in the absence of trauma. It also has been proposed that bleomycin has a direct toxic effect on the melanocytes, which stimulates increased melanin secretion.² The hyperpigmentation also may be due to pigmentary incontinence secondary to inflammation.⁵ Histopathologic findings usually are varied and nonspecific.² There may be a deep perivascular lymphocytic infiltrate, which is nonspecific but can be associated with drug-induced pathology.⁴ Bleomycin also is used to induce localized scleroderma in mouse-model research⁶ and has been reported to cause localized scleroderma at an infusion site or after an intralesional injection,^7,8 which is not typically reported in flagellate erythema, but bleomycin's sclerosing effects may have played a role in the visible and sclerosing atrophy noted in our patient. Yamamoto et al⁹ reported a similar case of dermal sclerosis induced by bleomycin.  

Flagellate hyperpigmentation typically lasts for up to 6 months.³ Patients with cutaneous manifestations from bleomycin therapy usually respond to steroid therapy and discontinuation of the drug. Bleomycin re-exposure should be avoided, as it may cause extension or widespread recurrence of flagellate hyperpigmentation.³ Postinflammatory pigment alteration may persist in patients with darker skin types and in patients with dramatic inciting inflammation.  

Atrophoderma of Pasini and Pierini is a form of dermal atrophy that presents with 1 or more sharply demarcated depressed patches. There is some debate whether it is a distinct entity or a primary atrophic morphea.¹⁰ Linear atrophoderma of Moulin has a similar morphology with hyperpigmented depressions and "cliff-drop" borders, but these lesions follow the lines of Blaschko.¹¹ Linear morphea initially can present as a linear erythematous streak but more commonly appears as a plaque-type morphea lesion that forms a scarlike band.¹² Erythema dyschromicum perstans is an ashy dermatosis characterized by gray or blue-brown macules seen in Fitzpatrick skin types III through V and typically is chronic and progressive.¹³  

The Diagnosis: Bleomycin-Induced Flagellate Hyperpigmentation 

Histopathology of the affected skin demonstrated a slight increase in collagen bundle thickness, a chronic dermal perivascular inflammation, and associated pigment incontinence with dermal melanophages compared to unaffected skin (Figure). CD34 was faintly decreased, and dermal mucin increased in affected skin. This postinflammatory pigmentary alteration with subtle dermal sclerosis had persisted unchanged for more than 5 years after cessation of bleomycin therapy. Topical hydroquinone, physical blocker photoprotection, and laser modalities such as the Q-switched alexandrite (755-nm)/Nd:YAG (1064-nm) and ablative CO₂ resurfacing lasers were attempted with minimal overall impact on cosmesis. 

Bleomycin is a chemotherapeutic antibiotic that has been commonly used to treat Hodgkin lymphoma, germ cell tumors, and recurrent malignant pleural effusions.¹ The drug is inactivated in most tissues by the enzyme bleomycin hydrolase. This enzyme is not present in skin and lung tissue; as a result, these organs are the most common sites of bleomycin toxicity.¹ There are a variety of cutaneous effects associated with bleomycin including alopecia, hyperpigmentation, acral erythema, Raynaud phenomenon, and nail dystrophy.² Flagellate hyperpigmentation is a less common cutaneous toxicity. It is an unusual eruption that appears as whiplike linear streaks on the upper chest and back, limbs, and flanks.³ This cutaneous manifestation was once thought to be specific to bleomycin use; however, it also has been described in dermatomyositis, adult-onset Still disease, and after the ingestion of uncooked or undercooked shiitake mushrooms.⁴ Flagellate hyperpigmentation also was once thought to be dose dependent; however, it has been described in even very small doses.⁵ The eruption has been described as independent of the route of drug administration, appearing with intravenous, subcutaneous, and intramuscular bleomycin.² The association of bleomycin and flagellate hyperpigmentation has been reported since 1970; however, it is less commonly seen in clinical practice with the declining use of bleomycin.¹  

The exact mechanism for the hyperpigmentation is unknown. It has been proposed that the linear lesions are related to areas of pruritus and subsequent excoriations.¹ Dermatographism may be present to a limited extent, but it is unlikely to be a chief cause of flagellate hyperpigmentation, as linear streaks have been reported in the absence of trauma. It also has been proposed that bleomycin has a direct toxic effect on the melanocytes, which stimulates increased melanin secretion.² The hyperpigmentation also may be due to pigmentary incontinence secondary to inflammation.⁵ Histopathologic findings usually are varied and nonspecific.² There may be a deep perivascular lymphocytic infiltrate, which is nonspecific but can be associated with drug-induced pathology.⁴ Bleomycin also is used to induce localized scleroderma in mouse-model research⁶ and has been reported to cause localized scleroderma at an infusion site or after an intralesional injection,^7,8 which is not typically reported in flagellate erythema, but bleomycin's sclerosing effects may have played a role in the visible and sclerosing atrophy noted in our patient. Yamamoto et al⁹ reported a similar case of dermal sclerosis induced by bleomycin.  

Flagellate hyperpigmentation typically lasts for up to 6 months.³ Patients with cutaneous manifestations from bleomycin therapy usually respond to steroid therapy and discontinuation of the drug. Bleomycin re-exposure should be avoided, as it may cause extension or widespread recurrence of flagellate hyperpigmentation.³ Postinflammatory pigment alteration may persist in patients with darker skin types and in patients with dramatic inciting inflammation.  

Atrophoderma of Pasini and Pierini is a form of dermal atrophy that presents with 1 or more sharply demarcated depressed patches. There is some debate whether it is a distinct entity or a primary atrophic morphea.¹⁰ Linear atrophoderma of Moulin has a similar morphology with hyperpigmented depressions and "cliff-drop" borders, but these lesions follow the lines of Blaschko.¹¹ Linear morphea initially can present as a linear erythematous streak but more commonly appears as a plaque-type morphea lesion that forms a scarlike band.¹² Erythema dyschromicum perstans is an ashy dermatosis characterized by gray or blue-brown macules seen in Fitzpatrick skin types III through V and typically is chronic and progressive.¹³  

The Diagnosis: Bleomycin-Induced Flagellate Hyperpigmentation 

Histopathology of the affected skin demonstrated a slight increase in collagen bundle thickness, a chronic dermal perivascular inflammation, and associated pigment incontinence with dermal melanophages compared to unaffected skin (Figure). CD34 was faintly decreased, and dermal mucin increased in affected skin. This postinflammatory pigmentary alteration with subtle dermal sclerosis had persisted unchanged for more than 5 years after cessation of bleomycin therapy. Topical hydroquinone, physical blocker photoprotection, and laser modalities such as the Q-switched alexandrite (755-nm)/Nd:YAG (1064-nm) and ablative CO₂ resurfacing lasers were attempted with minimal overall impact on cosmesis. 

Bleomycin is a chemotherapeutic antibiotic that has been commonly used to treat Hodgkin lymphoma, germ cell tumors, and recurrent malignant pleural effusions.¹ The drug is inactivated in most tissues by the enzyme bleomycin hydrolase. This enzyme is not present in skin and lung tissue; as a result, these organs are the most common sites of bleomycin toxicity.¹ There are a variety of cutaneous effects associated with bleomycin including alopecia, hyperpigmentation, acral erythema, Raynaud phenomenon, and nail dystrophy.² Flagellate hyperpigmentation is a less common cutaneous toxicity. It is an unusual eruption that appears as whiplike linear streaks on the upper chest and back, limbs, and flanks.³ This cutaneous manifestation was once thought to be specific to bleomycin use; however, it also has been described in dermatomyositis, adult-onset Still disease, and after the ingestion of uncooked or undercooked shiitake mushrooms.⁴ Flagellate hyperpigmentation also was once thought to be dose dependent; however, it has been described in even very small doses.⁵ The eruption has been described as independent of the route of drug administration, appearing with intravenous, subcutaneous, and intramuscular bleomycin.² The association of bleomycin and flagellate hyperpigmentation has been reported since 1970; however, it is less commonly seen in clinical practice with the declining use of bleomycin.¹  

The exact mechanism for the hyperpigmentation is unknown. It has been proposed that the linear lesions are related to areas of pruritus and subsequent excoriations.¹ Dermatographism may be present to a limited extent, but it is unlikely to be a chief cause of flagellate hyperpigmentation, as linear streaks have been reported in the absence of trauma. It also has been proposed that bleomycin has a direct toxic effect on the melanocytes, which stimulates increased melanin secretion.² The hyperpigmentation also may be due to pigmentary incontinence secondary to inflammation.⁵ Histopathologic findings usually are varied and nonspecific.² There may be a deep perivascular lymphocytic infiltrate, which is nonspecific but can be associated with drug-induced pathology.⁴ Bleomycin also is used to induce localized scleroderma in mouse-model research⁶ and has been reported to cause localized scleroderma at an infusion site or after an intralesional injection,^7,8 which is not typically reported in flagellate erythema, but bleomycin's sclerosing effects may have played a role in the visible and sclerosing atrophy noted in our patient. Yamamoto et al⁹ reported a similar case of dermal sclerosis induced by bleomycin.  

Flagellate hyperpigmentation typically lasts for up to 6 months.³ Patients with cutaneous manifestations from bleomycin therapy usually respond to steroid therapy and discontinuation of the drug. Bleomycin re-exposure should be avoided, as it may cause extension or widespread recurrence of flagellate hyperpigmentation.³ Postinflammatory pigment alteration may persist in patients with darker skin types and in patients with dramatic inciting inflammation.  

Atrophoderma of Pasini and Pierini is a form of dermal atrophy that presents with 1 or more sharply demarcated depressed patches. There is some debate whether it is a distinct entity or a primary atrophic morphea.¹⁰ Linear atrophoderma of Moulin has a similar morphology with hyperpigmented depressions and "cliff-drop" borders, but these lesions follow the lines of Blaschko.¹¹ Linear morphea initially can present as a linear erythematous streak but more commonly appears as a plaque-type morphea lesion that forms a scarlike band.¹² Erythema dyschromicum perstans is an ashy dermatosis characterized by gray or blue-brown macules seen in Fitzpatrick skin types III through V and typically is chronic and progressive.¹³  

The Diagnosis: Irritant Contact Dermatitis  

A slang term for volatile alkyl nitrites, poppers are inhaled for recreational purposes. They produce    rapid-onset euphoria and sexual arousal, as well as relax anal and vaginal sphincters, facilitating sexual intercourse. Alkyl nitrites initially were developed to treat coronary disease and angina but were replaced by more potent drugs.¹ Because of their psychoactive effects and smooth muscle relaxation properties, they are widely used by homosexual and bisexual men.^1-3 The term poppers was originated by the sound generated when the glass vials are crushed; currently, they also may be found in other formats.¹  

Nausea, hypotension, and headache are mild common adverse effects of volatile alkyl nitrites¹; cardiac arrhythmia, oxidative hemolysis,⁴ and poppers maculopathy^5,6 with permanent eye damage also have been reported.⁷ On the skin, volatile alkyl nitrites induce irritant contact dermatitis that heals without scarring, characteristically involving the face and upper thoracic region, as they are volatile vapors.² However, the reaction can occur elsewhere. There have been reports of contact dermatitis on other locations, such as the thigh or the ankle, due to vials broken while stored in pockets or on the cuff of the socks.¹ There also is a report of irritant contact dermatitis manifesting as a penile ulcer.³ Albeit rare, allergic contact dermatitis to volatile alkyl nitrites and other nitrites also can occur.⁸  

The abuse of alkyl nitrites may increase the risk for sexually transmitted infections (STIs), as they may decrease safer sexual practices and increase the propensity to engage in risky sexual behavior. It has been suggested to screen for STIs in patients with history of volatile alkyl nitrite use. In the past, volatile alkyl nitrites were believed to be a potential vector of human immunodeficiency virus.⁹ Other popular drugs used in social context or "club drugs," such as 3,4-methylenedioxymethamphetamine, gamma hydroxybutyrate, methamphetamine, and ketamine, do not produce irritant dermatitis as an adverse cutaneous reaction.¹⁰ The differential diagnosis in our patient included herpes simplex virus and contagious impetigo¹ as well as bullous lupus erythematosus and periorificial dermatitis; however, the clinical picture, acute onset of the reaction, and the patient's medical history were critical in making the correct diagnosis.  

The patient was treated with topical hydrocortisone and fusidic acid cream twice daily for 7 days with complete response. Sexually transmitted infection screening was unremarkable. We suggest performing an STI workup on patients with history of volatile alkyl nitrite use. 

The Diagnosis: Irritant Contact Dermatitis  

A slang term for volatile alkyl nitrites, poppers are inhaled for recreational purposes. They produce    rapid-onset euphoria and sexual arousal, as well as relax anal and vaginal sphincters, facilitating sexual intercourse. Alkyl nitrites initially were developed to treat coronary disease and angina but were replaced by more potent drugs.¹ Because of their psychoactive effects and smooth muscle relaxation properties, they are widely used by homosexual and bisexual men.^1-3 The term poppers was originated by the sound generated when the glass vials are crushed; currently, they also may be found in other formats.¹  

Nausea, hypotension, and headache are mild common adverse effects of volatile alkyl nitrites¹; cardiac arrhythmia, oxidative hemolysis,⁴ and poppers maculopathy^5,6 with permanent eye damage also have been reported.⁷ On the skin, volatile alkyl nitrites induce irritant contact dermatitis that heals without scarring, characteristically involving the face and upper thoracic region, as they are volatile vapors.² However, the reaction can occur elsewhere. There have been reports of contact dermatitis on other locations, such as the thigh or the ankle, due to vials broken while stored in pockets or on the cuff of the socks.¹ There also is a report of irritant contact dermatitis manifesting as a penile ulcer.³ Albeit rare, allergic contact dermatitis to volatile alkyl nitrites and other nitrites also can occur.⁸  

The abuse of alkyl nitrites may increase the risk for sexually transmitted infections (STIs), as they may decrease safer sexual practices and increase the propensity to engage in risky sexual behavior. It has been suggested to screen for STIs in patients with history of volatile alkyl nitrite use. In the past, volatile alkyl nitrites were believed to be a potential vector of human immunodeficiency virus.⁹ Other popular drugs used in social context or "club drugs," such as 3,4-methylenedioxymethamphetamine, gamma hydroxybutyrate, methamphetamine, and ketamine, do not produce irritant dermatitis as an adverse cutaneous reaction.¹⁰ The differential diagnosis in our patient included herpes simplex virus and contagious impetigo¹ as well as bullous lupus erythematosus and periorificial dermatitis; however, the clinical picture, acute onset of the reaction, and the patient's medical history were critical in making the correct diagnosis.  

The patient was treated with topical hydrocortisone and fusidic acid cream twice daily for 7 days with complete response. Sexually transmitted infection screening was unremarkable. We suggest performing an STI workup on patients with history of volatile alkyl nitrite use. 

The Diagnosis: Irritant Contact Dermatitis  

A slang term for volatile alkyl nitrites, poppers are inhaled for recreational purposes. They produce    rapid-onset euphoria and sexual arousal, as well as relax anal and vaginal sphincters, facilitating sexual intercourse. Alkyl nitrites initially were developed to treat coronary disease and angina but were replaced by more potent drugs.¹ Because of their psychoactive effects and smooth muscle relaxation properties, they are widely used by homosexual and bisexual men.^1-3 The term poppers was originated by the sound generated when the glass vials are crushed; currently, they also may be found in other formats.¹  

Nausea, hypotension, and headache are mild common adverse effects of volatile alkyl nitrites¹; cardiac arrhythmia, oxidative hemolysis,⁴ and poppers maculopathy^5,6 with permanent eye damage also have been reported.⁷ On the skin, volatile alkyl nitrites induce irritant contact dermatitis that heals without scarring, characteristically involving the face and upper thoracic region, as they are volatile vapors.² However, the reaction can occur elsewhere. There have been reports of contact dermatitis on other locations, such as the thigh or the ankle, due to vials broken while stored in pockets or on the cuff of the socks.¹ There also is a report of irritant contact dermatitis manifesting as a penile ulcer.³ Albeit rare, allergic contact dermatitis to volatile alkyl nitrites and other nitrites also can occur.⁸  

The abuse of alkyl nitrites may increase the risk for sexually transmitted infections (STIs), as they may decrease safer sexual practices and increase the propensity to engage in risky sexual behavior. It has been suggested to screen for STIs in patients with history of volatile alkyl nitrite use. In the past, volatile alkyl nitrites were believed to be a potential vector of human immunodeficiency virus.⁹ Other popular drugs used in social context or "club drugs," such as 3,4-methylenedioxymethamphetamine, gamma hydroxybutyrate, methamphetamine, and ketamine, do not produce irritant dermatitis as an adverse cutaneous reaction.¹⁰ The differential diagnosis in our patient included herpes simplex virus and contagious impetigo¹ as well as bullous lupus erythematosus and periorificial dermatitis; however, the clinical picture, acute onset of the reaction, and the patient's medical history were critical in making the correct diagnosis.  

The patient was treated with topical hydrocortisone and fusidic acid cream twice daily for 7 days with complete response. Sexually transmitted infection screening was unremarkable. We suggest performing an STI workup on patients with history of volatile alkyl nitrite use. 

The Diagnosis: Cutaneous Sarcoidosis  

Histologic examination of the shave biopsy showed focal parakeratosis, irregular epidermal hyperplasia, and multiple noncaseating naked granulomas with occasional multinucleated giant cells in the dermis (Figure, A). The granulomas were surrounded by mild lymphocytic infiltration with rare eosinophils (Figure, B). Periodic acid-Schiff and Fite stains were negative for organisms, and polariscopic examination was negative; these findings confirmed the diagnosis of cutaneous sarcoidosis. Topical or intralesional steroids were recommended, but our patient declined treatment given that the lesions were asymptomatic.  

Sarcoidosis is a multisystem granulomatous disease of unknown etiology that affects the skin in approximately 25% of patients.¹ Cutaneous lesions manifest in 2 forms: specific and nonspecific. Noncaseating granulomas are considered specific. Nonspecific lesions include erythema nodosum, calcinosis cutis, Sweet syndrome, and nail clubbing. The most common sites of specific sarcoidosis lesions include the face, lips, neck, upper trunk, and extremities. Few cases have reported cutaneous sarcoidosis involving the genitalia; most reports describe vulvar cutaneous sarcoidosis.^2-4 Although there have been reports of sarcoidosis involving the epididymis and testes, which presented as scrotal masses, cutaneous scrotal involvement with the skin as the primary site of involvement is rare.^5,6 McLaughlin et al⁵ reported an extensive, pruritic, and eczematous eruption of the scrotum with associated edema and tenderness. Wei et al⁶ reported cutaneous sarcoidosis in the form of multiple indurated papules involving the penis and scrotum, similar to our case.  

Comparing our patient to the case reported by Wei et al,⁶ both patients had Fitzpatrick skin type V or VI and systemic involvement including pulmonary disease. However, Wei et al⁶ did not clearly mention if the cutaneous manifestations preceded the diagnosis of systemic sarcoidosis or if they were present at the time of the diagnosis. Our patient developed cutaneous lesions 4 years after being diagnosed with systemic sarcoidosis from hilar lymphadenopathy. In addition to the scrotal lesions, he also had a lesion of lupus pernio presenting as a violaceous to brown plaque on the tip of the nose. Although both patients denied pruritus, the other patient's lesions were painful.⁶ Wei et al⁶ mentioned that treatment with topical, intralesional, and systemic steroids failed, and the patient's lesions continued to progress. Generally, topical and intralesional steroids are considered mainstay treatment of cutaneous sarcoidosis despite insufficient data to support their efficacy.⁷  

The differential diagnosis of papules on the scrotum can be broad. Our provisional diagnoses for this particular morphology of small, flesh-colored, shiny, polygonal, flat-topped papules included condyloma acuminatum; lichen planus; idiopathic scrotal calcinosis; steatocystoma multiplex; and sarcoidosis (although uncommon for the site), given the history of pulmonary involvement. We considered a diagnosis of condyloma acuminatum, but the lesions were too shiny and smooth. On histology, condyloma acuminatum shows a hyperkeratotic and parakeratotic stratum corneum, an exophytic growth with marked acanthosis, and superficially located koilocytes. Morphologically, our patient's lesions resembled genital lichen planus. However, Wickham striae were absent, and our patient's lesions were asymptomatic while lesions of lichen planus usually are pruritic. Histologically, lichen planus is characterized by hyperkeratosis, hypergranulosis, sawtooth rete ridges, and lichenoid interface inflammation. Idiopathic scrotal calcinosis also could be included in the differential; however, the lesions would look whiter and firmer than those of our patient, and biopsy will clearly show calcium deposition. Steatocystoma multiplex is another condition that can affect the scrotum, along with the trunk, axillae, extremities, and neck. However, the lesions are expected to discharge oily material if squeezed and have a characteristic corrugated eosinophilic cuticle lining a cyst histologically.  

Although it is undetermined if the risk for systemic involvement increases in patients with cutaneous sarcoidosis, evaluation for probable systemic involvement is necessary.¹ Because cutaneous sarcoidosis generally can precede any systemic involvement, it would be reasonable to consider skin biopsies in patients who present with atypical wartlike lesions on the scrotum and penis to rule out sarcoidosis. 

The Diagnosis: Cutaneous Sarcoidosis  

Histologic examination of the shave biopsy showed focal parakeratosis, irregular epidermal hyperplasia, and multiple noncaseating naked granulomas with occasional multinucleated giant cells in the dermis (Figure, A). The granulomas were surrounded by mild lymphocytic infiltration with rare eosinophils (Figure, B). Periodic acid-Schiff and Fite stains were negative for organisms, and polariscopic examination was negative; these findings confirmed the diagnosis of cutaneous sarcoidosis. Topical or intralesional steroids were recommended, but our patient declined treatment given that the lesions were asymptomatic.  

Sarcoidosis is a multisystem granulomatous disease of unknown etiology that affects the skin in approximately 25% of patients.¹ Cutaneous lesions manifest in 2 forms: specific and nonspecific. Noncaseating granulomas are considered specific. Nonspecific lesions include erythema nodosum, calcinosis cutis, Sweet syndrome, and nail clubbing. The most common sites of specific sarcoidosis lesions include the face, lips, neck, upper trunk, and extremities. Few cases have reported cutaneous sarcoidosis involving the genitalia; most reports describe vulvar cutaneous sarcoidosis.^2-4 Although there have been reports of sarcoidosis involving the epididymis and testes, which presented as scrotal masses, cutaneous scrotal involvement with the skin as the primary site of involvement is rare.^5,6 McLaughlin et al⁵ reported an extensive, pruritic, and eczematous eruption of the scrotum with associated edema and tenderness. Wei et al⁶ reported cutaneous sarcoidosis in the form of multiple indurated papules involving the penis and scrotum, similar to our case.  

Comparing our patient to the case reported by Wei et al,⁶ both patients had Fitzpatrick skin type V or VI and systemic involvement including pulmonary disease. However, Wei et al⁶ did not clearly mention if the cutaneous manifestations preceded the diagnosis of systemic sarcoidosis or if they were present at the time of the diagnosis. Our patient developed cutaneous lesions 4 years after being diagnosed with systemic sarcoidosis from hilar lymphadenopathy. In addition to the scrotal lesions, he also had a lesion of lupus pernio presenting as a violaceous to brown plaque on the tip of the nose. Although both patients denied pruritus, the other patient's lesions were painful.⁶ Wei et al⁶ mentioned that treatment with topical, intralesional, and systemic steroids failed, and the patient's lesions continued to progress. Generally, topical and intralesional steroids are considered mainstay treatment of cutaneous sarcoidosis despite insufficient data to support their efficacy.⁷  

The differential diagnosis of papules on the scrotum can be broad. Our provisional diagnoses for this particular morphology of small, flesh-colored, shiny, polygonal, flat-topped papules included condyloma acuminatum; lichen planus; idiopathic scrotal calcinosis; steatocystoma multiplex; and sarcoidosis (although uncommon for the site), given the history of pulmonary involvement. We considered a diagnosis of condyloma acuminatum, but the lesions were too shiny and smooth. On histology, condyloma acuminatum shows a hyperkeratotic and parakeratotic stratum corneum, an exophytic growth with marked acanthosis, and superficially located koilocytes. Morphologically, our patient's lesions resembled genital lichen planus. However, Wickham striae were absent, and our patient's lesions were asymptomatic while lesions of lichen planus usually are pruritic. Histologically, lichen planus is characterized by hyperkeratosis, hypergranulosis, sawtooth rete ridges, and lichenoid interface inflammation. Idiopathic scrotal calcinosis also could be included in the differential; however, the lesions would look whiter and firmer than those of our patient, and biopsy will clearly show calcium deposition. Steatocystoma multiplex is another condition that can affect the scrotum, along with the trunk, axillae, extremities, and neck. However, the lesions are expected to discharge oily material if squeezed and have a characteristic corrugated eosinophilic cuticle lining a cyst histologically.  

Although it is undetermined if the risk for systemic involvement increases in patients with cutaneous sarcoidosis, evaluation for probable systemic involvement is necessary.¹ Because cutaneous sarcoidosis generally can precede any systemic involvement, it would be reasonable to consider skin biopsies in patients who present with atypical wartlike lesions on the scrotum and penis to rule out sarcoidosis. 

The Diagnosis: Cutaneous Sarcoidosis  

Histologic examination of the shave biopsy showed focal parakeratosis, irregular epidermal hyperplasia, and multiple noncaseating naked granulomas with occasional multinucleated giant cells in the dermis (Figure, A). The granulomas were surrounded by mild lymphocytic infiltration with rare eosinophils (Figure, B). Periodic acid-Schiff and Fite stains were negative for organisms, and polariscopic examination was negative; these findings confirmed the diagnosis of cutaneous sarcoidosis. Topical or intralesional steroids were recommended, but our patient declined treatment given that the lesions were asymptomatic.  

Sarcoidosis is a multisystem granulomatous disease of unknown etiology that affects the skin in approximately 25% of patients.¹ Cutaneous lesions manifest in 2 forms: specific and nonspecific. Noncaseating granulomas are considered specific. Nonspecific lesions include erythema nodosum, calcinosis cutis, Sweet syndrome, and nail clubbing. The most common sites of specific sarcoidosis lesions include the face, lips, neck, upper trunk, and extremities. Few cases have reported cutaneous sarcoidosis involving the genitalia; most reports describe vulvar cutaneous sarcoidosis.^2-4 Although there have been reports of sarcoidosis involving the epididymis and testes, which presented as scrotal masses, cutaneous scrotal involvement with the skin as the primary site of involvement is rare.^5,6 McLaughlin et al⁵ reported an extensive, pruritic, and eczematous eruption of the scrotum with associated edema and tenderness. Wei et al⁶ reported cutaneous sarcoidosis in the form of multiple indurated papules involving the penis and scrotum, similar to our case.  

Comparing our patient to the case reported by Wei et al,⁶ both patients had Fitzpatrick skin type V or VI and systemic involvement including pulmonary disease. However, Wei et al⁶ did not clearly mention if the cutaneous manifestations preceded the diagnosis of systemic sarcoidosis or if they were present at the time of the diagnosis. Our patient developed cutaneous lesions 4 years after being diagnosed with systemic sarcoidosis from hilar lymphadenopathy. In addition to the scrotal lesions, he also had a lesion of lupus pernio presenting as a violaceous to brown plaque on the tip of the nose. Although both patients denied pruritus, the other patient's lesions were painful.⁶ Wei et al⁶ mentioned that treatment with topical, intralesional, and systemic steroids failed, and the patient's lesions continued to progress. Generally, topical and intralesional steroids are considered mainstay treatment of cutaneous sarcoidosis despite insufficient data to support their efficacy.⁷  

The differential diagnosis of papules on the scrotum can be broad. Our provisional diagnoses for this particular morphology of small, flesh-colored, shiny, polygonal, flat-topped papules included condyloma acuminatum; lichen planus; idiopathic scrotal calcinosis; steatocystoma multiplex; and sarcoidosis (although uncommon for the site), given the history of pulmonary involvement. We considered a diagnosis of condyloma acuminatum, but the lesions were too shiny and smooth. On histology, condyloma acuminatum shows a hyperkeratotic and parakeratotic stratum corneum, an exophytic growth with marked acanthosis, and superficially located koilocytes. Morphologically, our patient's lesions resembled genital lichen planus. However, Wickham striae were absent, and our patient's lesions were asymptomatic while lesions of lichen planus usually are pruritic. Histologically, lichen planus is characterized by hyperkeratosis, hypergranulosis, sawtooth rete ridges, and lichenoid interface inflammation. Idiopathic scrotal calcinosis also could be included in the differential; however, the lesions would look whiter and firmer than those of our patient, and biopsy will clearly show calcium deposition. Steatocystoma multiplex is another condition that can affect the scrotum, along with the trunk, axillae, extremities, and neck. However, the lesions are expected to discharge oily material if squeezed and have a characteristic corrugated eosinophilic cuticle lining a cyst histologically.  

Although it is undetermined if the risk for systemic involvement increases in patients with cutaneous sarcoidosis, evaluation for probable systemic involvement is necessary.¹ Because cutaneous sarcoidosis generally can precede any systemic involvement, it would be reasonable to consider skin biopsies in patients who present with atypical wartlike lesions on the scrotum and penis to rule out sarcoidosis. 

The Diagnosis: Bullous Systemic Lupus Erythematosus  

Bullous systemic lupus erythematosus (BSLE) is a rare blistering disease that affects patients with systemic lupus erythematosus (SLE). Our patient had a several-year history of SLE and was being managed by a rheumatologist. She was taking hydroxychloroquine at the time of the flare. Although BSLE tends to present in those with SLE that has already been diagnosed, BSLE has been reported as a possible initial manifestation of SLE.¹  

Bullous systemic lupus erythematosus is estimated to occur in less than 5% of patients with SLE and is more common in black women between the second and third decades of life,² though it also can be seen in the pediatric population.³ The lesions of BSLE usually present as subepidermal blisters often located on the face, neck, and arms on an erythematous or possibly urticarial base. Although non-BSLE vesiculobullous eruptions may be seen in patients with SLE, BSLE is differentiated from these other eruptions by its appearance on sun-exposed and non-sun-exposed areas of the body, while other vesiculobullous eruptions associated with SLE typically are limited to sun-exposed sites.⁴  

Due to its clinical presentation overlapping with several vesiculobullous conditions, a set of diagnostic criteria have been suggested for BSLE, including the following: (1) fulfillment of the American Rheumatism Association's criteria for SLE⁵; (2) a new-onset vesiculobullous eruption, primarily on sun-exposed skin; (3) histology showing a subepidermal blister with a predominantly neutrophilic infiltrate; (4) presence of IgG, IgA, IgM, and C3 at the basement membrane zone; (5) evidence of antibodies to type VII collagen; and (6) immunoelectron microscopy showing codistribution of immunoglobulin deposits with anchoring fibrils/type VII collagen. To meet the diagnosis of type I BSLE, all 6 criteria must be satisfied. To meet the diagnosis of type II BSLE, only criteria 1 to 4 need to be satisfied.⁶  

Patients with BSLE may be presumed to have a different but clinically similar vesiculobullous condition (eg, bullous pemphigoid, cutaneous manifestations of SLE) and may be started on systemic corticosteroids. However, BSLE patients often do not show great improvement while on corticosteroids and may even flare shortly after beginning systemic corticosteroid treatment. The current treatment of choice for BSLE is dapsone, a sulfa drug that is thought to exhibit its anti-inflammatory properties via the inhibition of the alternative pathway of the complement system and through the inhibition of polymorphonuclear leukocyte functions.⁷ A response to dapsone helps differentiate BSLE from histopathologically and immunopathologically identical conditions such as epidermolysis bullosa acquisita.⁴ Bullous systemic lupus erythematosus can be differentiated from dermatitis herpetiformis with the presence of antigliadin and antitissue transglutaminase antibodies, which are found in the latter.  Additionally, BSLE may show the presence of IgG and IgM deposition in addition to IgA deposition, as opposed to dermatitis herpetiformis where only IgA is found.⁸ The presence of these additional antibody depositions also help differentiate BSLE from linear IgA bullous dermatosis (LABD), as LABD will only have IgA depositions and often presents with an annular, crown of jewels-like appearance.  Finally, there is a well-described phenomenon of LABD being drug induced, particularly after a course of vancomycin,⁹ and such an association with vancomycin has not been documented for BSLE. 

Our patient was diagnosed with BSLE following the flare approximately 1.5 years prior to the current presentation. She had been started on dapsone 75 mg daily at that time and was taking 75 mg at the time of presentation. She was admitted and treated as an inpatient with high-dose (1 mg/kg) intravenous prednisone due to the extensive current flare. 

The Diagnosis: Bullous Systemic Lupus Erythematosus  

Bullous systemic lupus erythematosus (BSLE) is a rare blistering disease that affects patients with systemic lupus erythematosus (SLE). Our patient had a several-year history of SLE and was being managed by a rheumatologist. She was taking hydroxychloroquine at the time of the flare. Although BSLE tends to present in those with SLE that has already been diagnosed, BSLE has been reported as a possible initial manifestation of SLE.¹  

Bullous systemic lupus erythematosus is estimated to occur in less than 5% of patients with SLE and is more common in black women between the second and third decades of life,² though it also can be seen in the pediatric population.³ The lesions of BSLE usually present as subepidermal blisters often located on the face, neck, and arms on an erythematous or possibly urticarial base. Although non-BSLE vesiculobullous eruptions may be seen in patients with SLE, BSLE is differentiated from these other eruptions by its appearance on sun-exposed and non-sun-exposed areas of the body, while other vesiculobullous eruptions associated with SLE typically are limited to sun-exposed sites.⁴  

Due to its clinical presentation overlapping with several vesiculobullous conditions, a set of diagnostic criteria have been suggested for BSLE, including the following: (1) fulfillment of the American Rheumatism Association's criteria for SLE⁵; (2) a new-onset vesiculobullous eruption, primarily on sun-exposed skin; (3) histology showing a subepidermal blister with a predominantly neutrophilic infiltrate; (4) presence of IgG, IgA, IgM, and C3 at the basement membrane zone; (5) evidence of antibodies to type VII collagen; and (6) immunoelectron microscopy showing codistribution of immunoglobulin deposits with anchoring fibrils/type VII collagen. To meet the diagnosis of type I BSLE, all 6 criteria must be satisfied. To meet the diagnosis of type II BSLE, only criteria 1 to 4 need to be satisfied.⁶  

Patients with BSLE may be presumed to have a different but clinically similar vesiculobullous condition (eg, bullous pemphigoid, cutaneous manifestations of SLE) and may be started on systemic corticosteroids. However, BSLE patients often do not show great improvement while on corticosteroids and may even flare shortly after beginning systemic corticosteroid treatment. The current treatment of choice for BSLE is dapsone, a sulfa drug that is thought to exhibit its anti-inflammatory properties via the inhibition of the alternative pathway of the complement system and through the inhibition of polymorphonuclear leukocyte functions.⁷ A response to dapsone helps differentiate BSLE from histopathologically and immunopathologically identical conditions such as epidermolysis bullosa acquisita.⁴ Bullous systemic lupus erythematosus can be differentiated from dermatitis herpetiformis with the presence of antigliadin and antitissue transglutaminase antibodies, which are found in the latter.  Additionally, BSLE may show the presence of IgG and IgM deposition in addition to IgA deposition, as opposed to dermatitis herpetiformis where only IgA is found.⁸ The presence of these additional antibody depositions also help differentiate BSLE from linear IgA bullous dermatosis (LABD), as LABD will only have IgA depositions and often presents with an annular, crown of jewels-like appearance.  Finally, there is a well-described phenomenon of LABD being drug induced, particularly after a course of vancomycin,⁹ and such an association with vancomycin has not been documented for BSLE. 

Our patient was diagnosed with BSLE following the flare approximately 1.5 years prior to the current presentation. She had been started on dapsone 75 mg daily at that time and was taking 75 mg at the time of presentation. She was admitted and treated as an inpatient with high-dose (1 mg/kg) intravenous prednisone due to the extensive current flare. 

The Diagnosis: Bullous Systemic Lupus Erythematosus  

Bullous systemic lupus erythematosus (BSLE) is a rare blistering disease that affects patients with systemic lupus erythematosus (SLE). Our patient had a several-year history of SLE and was being managed by a rheumatologist. She was taking hydroxychloroquine at the time of the flare. Although BSLE tends to present in those with SLE that has already been diagnosed, BSLE has been reported as a possible initial manifestation of SLE.¹  

Bullous systemic lupus erythematosus is estimated to occur in less than 5% of patients with SLE and is more common in black women between the second and third decades of life,² though it also can be seen in the pediatric population.³ The lesions of BSLE usually present as subepidermal blisters often located on the face, neck, and arms on an erythematous or possibly urticarial base. Although non-BSLE vesiculobullous eruptions may be seen in patients with SLE, BSLE is differentiated from these other eruptions by its appearance on sun-exposed and non-sun-exposed areas of the body, while other vesiculobullous eruptions associated with SLE typically are limited to sun-exposed sites.⁴  

Due to its clinical presentation overlapping with several vesiculobullous conditions, a set of diagnostic criteria have been suggested for BSLE, including the following: (1) fulfillment of the American Rheumatism Association's criteria for SLE⁵; (2) a new-onset vesiculobullous eruption, primarily on sun-exposed skin; (3) histology showing a subepidermal blister with a predominantly neutrophilic infiltrate; (4) presence of IgG, IgA, IgM, and C3 at the basement membrane zone; (5) evidence of antibodies to type VII collagen; and (6) immunoelectron microscopy showing codistribution of immunoglobulin deposits with anchoring fibrils/type VII collagen. To meet the diagnosis of type I BSLE, all 6 criteria must be satisfied. To meet the diagnosis of type II BSLE, only criteria 1 to 4 need to be satisfied.⁶  

Patients with BSLE may be presumed to have a different but clinically similar vesiculobullous condition (eg, bullous pemphigoid, cutaneous manifestations of SLE) and may be started on systemic corticosteroids. However, BSLE patients often do not show great improvement while on corticosteroids and may even flare shortly after beginning systemic corticosteroid treatment. The current treatment of choice for BSLE is dapsone, a sulfa drug that is thought to exhibit its anti-inflammatory properties via the inhibition of the alternative pathway of the complement system and through the inhibition of polymorphonuclear leukocyte functions.⁷ A response to dapsone helps differentiate BSLE from histopathologically and immunopathologically identical conditions such as epidermolysis bullosa acquisita.⁴ Bullous systemic lupus erythematosus can be differentiated from dermatitis herpetiformis with the presence of antigliadin and antitissue transglutaminase antibodies, which are found in the latter.  Additionally, BSLE may show the presence of IgG and IgM deposition in addition to IgA deposition, as opposed to dermatitis herpetiformis where only IgA is found.⁸ The presence of these additional antibody depositions also help differentiate BSLE from linear IgA bullous dermatosis (LABD), as LABD will only have IgA depositions and often presents with an annular, crown of jewels-like appearance.  Finally, there is a well-described phenomenon of LABD being drug induced, particularly after a course of vancomycin,⁹ and such an association with vancomycin has not been documented for BSLE. 

Our patient was diagnosed with BSLE following the flare approximately 1.5 years prior to the current presentation. She had been started on dapsone 75 mg daily at that time and was taking 75 mg at the time of presentation. She was admitted and treated as an inpatient with high-dose (1 mg/kg) intravenous prednisone due to the extensive current flare. 

The Diagnosis: Nipple Adenoma (Florid Papillomatosis of the Nipple) 

Biopsy of the nodule showed florid papillary hyperplasia of the ductal epithelium within the dermis that was sharply demarcated from the background stroma (Figure, A and B). Neither cytological nor architectural atypia were evident. There was no notable necrosis (Figure C). There was a background of fibrosis whereby the glandular ductal structures assumed a somewhat irregular growth pattern within the dermis with attendant hemorrhage. The patient underwent complete excision of the lesion. No evidence of carcinoma was seen on the final pathology, and the final margins were negative. 

First described in 1923 and fully characterized in 1955, nipple adenoma (also known as florid papillomatosis of the nipple) is a benign proliferative neoplasm that originates in the lactiferous ducts of the nipple.^1,2 It most commonly affects women aged 40 to 50 years (range, 0-89 years); less than 5% of cases are reported in men.^3,4 It predominantly is unilateral, with only rare cases of bilateral papillomatosis reported. Patients often present with serous or serosanguineous discharge and an itching or burning sensation. Symptoms may worsen with the menstrual cycle.⁴ On physical examination, it presents as an ill-defined red nodule on the nipple with crusting, erosion, or erythema of the nipple surface. Although imaging generally is not used to confirm the diagnosis, mammography should be performed prior to biopsy to rule out underlying breast pathology. Dermoscopy may show linear cherry red structures or red serpiginous and annular structures.^5,6 The differential diagnosis of nipple adenoma includes Paget disease of the breast, adenomyoepithelioma, subareolar subsclerosing duct hyperplasia, syringomatous adenoma, adenosis tumor, low-grade adenosquamous carcinoma, low-grade ductal carcinoma in situ, tubular carcinoma, and sweat gland tumors.³  

Microscopic features of nipple adenoma have been categorized into 4 subtypes: sclerosing papillomatosis, papillomatosis, adenosis, and a mixed pattern.^3,7 The tumors may have keratin cysts and focal necrosis but no atypia, and the myoepithelial cell layer is retained. Nipple adenomas show a glandular proliferation in the dermis that is relatively well circumscribed with glands that vary in appearance between a simple adenosislike pattern of growth to a papillary hyperplasia and/or usual ductal hyperplasia growth pattern. A pseudoinfiltrative pattern can occur when the glandular epithelium is entrapped within stromal fibrosis; however, the myoepithelial layer is retained. Occasionally, the glandular epithelium can grow in continuity with the surface squamous epithelium of the nipple, clinically simulating Paget disease of the breast.⁸ Immunohistochemical stains, specifically p63, p40, calponin 1, h-caldesmon, cytokeratin 5/6, CD10, and α; smooth muscle actin, highlight the myoepithelial cells, while cytokeratin 7 identifies the ductal epithelium, supporting the diagnosis.⁶ In addition to biopsy and microscopic tissue examination, touch preparation cytology, curettage cytology, and fine needle aspiration techniques have been used to perform cytologic examination of the lesions, aiding in identification of the benign or malignant nature of the neoplasm.⁶ Nipple adenoma also is referred to as florid papillomatosis of the nipple, papillary adenoma, erosive adenomatosis, and subareolar duct papillomatosis.⁷ 

Although nipple adenoma is a benign tumor, up to 16.5% of affected patients had an ipsilateral or contralateral mammary carcinoma.⁹ The majority arose coincidentally but separately in the same breast, and carcinoma arose directly from the nipple adenoma in 8 cases; 3 cases were carcinomas that arose in men.¹⁰ A definitive association or causal relationship between nipple adenoma and subsequent development of breast cancer has not been identified, and the incidence of nipple adenoma in patients with a positive family history of breast cancer has not been examined. Therefore, although various treatments including cryosurgery, nipple splitting enucleation, and Mohs micrographic surgery have been proposed, complete excision remains the gold standard of therapy. Regular breast examinations and digital mammography are necessary to screen for local recurrences.  

The Diagnosis: Nipple Adenoma (Florid Papillomatosis of the Nipple) 

Biopsy of the nodule showed florid papillary hyperplasia of the ductal epithelium within the dermis that was sharply demarcated from the background stroma (Figure, A and B). Neither cytological nor architectural atypia were evident. There was no notable necrosis (Figure C). There was a background of fibrosis whereby the glandular ductal structures assumed a somewhat irregular growth pattern within the dermis with attendant hemorrhage. The patient underwent complete excision of the lesion. No evidence of carcinoma was seen on the final pathology, and the final margins were negative. 

First described in 1923 and fully characterized in 1955, nipple adenoma (also known as florid papillomatosis of the nipple) is a benign proliferative neoplasm that originates in the lactiferous ducts of the nipple.^1,2 It most commonly affects women aged 40 to 50 years (range, 0-89 years); less than 5% of cases are reported in men.^3,4 It predominantly is unilateral, with only rare cases of bilateral papillomatosis reported. Patients often present with serous or serosanguineous discharge and an itching or burning sensation. Symptoms may worsen with the menstrual cycle.⁴ On physical examination, it presents as an ill-defined red nodule on the nipple with crusting, erosion, or erythema of the nipple surface. Although imaging generally is not used to confirm the diagnosis, mammography should be performed prior to biopsy to rule out underlying breast pathology. Dermoscopy may show linear cherry red structures or red serpiginous and annular structures.^5,6 The differential diagnosis of nipple adenoma includes Paget disease of the breast, adenomyoepithelioma, subareolar subsclerosing duct hyperplasia, syringomatous adenoma, adenosis tumor, low-grade adenosquamous carcinoma, low-grade ductal carcinoma in situ, tubular carcinoma, and sweat gland tumors.³  

Microscopic features of nipple adenoma have been categorized into 4 subtypes: sclerosing papillomatosis, papillomatosis, adenosis, and a mixed pattern.^3,7 The tumors may have keratin cysts and focal necrosis but no atypia, and the myoepithelial cell layer is retained. Nipple adenomas show a glandular proliferation in the dermis that is relatively well circumscribed with glands that vary in appearance between a simple adenosislike pattern of growth to a papillary hyperplasia and/or usual ductal hyperplasia growth pattern. A pseudoinfiltrative pattern can occur when the glandular epithelium is entrapped within stromal fibrosis; however, the myoepithelial layer is retained. Occasionally, the glandular epithelium can grow in continuity with the surface squamous epithelium of the nipple, clinically simulating Paget disease of the breast.⁸ Immunohistochemical stains, specifically p63, p40, calponin 1, h-caldesmon, cytokeratin 5/6, CD10, and α; smooth muscle actin, highlight the myoepithelial cells, while cytokeratin 7 identifies the ductal epithelium, supporting the diagnosis.⁶ In addition to biopsy and microscopic tissue examination, touch preparation cytology, curettage cytology, and fine needle aspiration techniques have been used to perform cytologic examination of the lesions, aiding in identification of the benign or malignant nature of the neoplasm.⁶ Nipple adenoma also is referred to as florid papillomatosis of the nipple, papillary adenoma, erosive adenomatosis, and subareolar duct papillomatosis.⁷ 

Although nipple adenoma is a benign tumor, up to 16.5% of affected patients had an ipsilateral or contralateral mammary carcinoma.⁹ The majority arose coincidentally but separately in the same breast, and carcinoma arose directly from the nipple adenoma in 8 cases; 3 cases were carcinomas that arose in men.¹⁰ A definitive association or causal relationship between nipple adenoma and subsequent development of breast cancer has not been identified, and the incidence of nipple adenoma in patients with a positive family history of breast cancer has not been examined. Therefore, although various treatments including cryosurgery, nipple splitting enucleation, and Mohs micrographic surgery have been proposed, complete excision remains the gold standard of therapy. Regular breast examinations and digital mammography are necessary to screen for local recurrences.  

The Diagnosis: Nipple Adenoma (Florid Papillomatosis of the Nipple) 

Biopsy of the nodule showed florid papillary hyperplasia of the ductal epithelium within the dermis that was sharply demarcated from the background stroma (Figure, A and B). Neither cytological nor architectural atypia were evident. There was no notable necrosis (Figure C). There was a background of fibrosis whereby the glandular ductal structures assumed a somewhat irregular growth pattern within the dermis with attendant hemorrhage. The patient underwent complete excision of the lesion. No evidence of carcinoma was seen on the final pathology, and the final margins were negative. 

First described in 1923 and fully characterized in 1955, nipple adenoma (also known as florid papillomatosis of the nipple) is a benign proliferative neoplasm that originates in the lactiferous ducts of the nipple.^1,2 It most commonly affects women aged 40 to 50 years (range, 0-89 years); less than 5% of cases are reported in men.^3,4 It predominantly is unilateral, with only rare cases of bilateral papillomatosis reported. Patients often present with serous or serosanguineous discharge and an itching or burning sensation. Symptoms may worsen with the menstrual cycle.⁴ On physical examination, it presents as an ill-defined red nodule on the nipple with crusting, erosion, or erythema of the nipple surface. Although imaging generally is not used to confirm the diagnosis, mammography should be performed prior to biopsy to rule out underlying breast pathology. Dermoscopy may show linear cherry red structures or red serpiginous and annular structures.^5,6 The differential diagnosis of nipple adenoma includes Paget disease of the breast, adenomyoepithelioma, subareolar subsclerosing duct hyperplasia, syringomatous adenoma, adenosis tumor, low-grade adenosquamous carcinoma, low-grade ductal carcinoma in situ, tubular carcinoma, and sweat gland tumors.³  

Microscopic features of nipple adenoma have been categorized into 4 subtypes: sclerosing papillomatosis, papillomatosis, adenosis, and a mixed pattern.^3,7 The tumors may have keratin cysts and focal necrosis but no atypia, and the myoepithelial cell layer is retained. Nipple adenomas show a glandular proliferation in the dermis that is relatively well circumscribed with glands that vary in appearance between a simple adenosislike pattern of growth to a papillary hyperplasia and/or usual ductal hyperplasia growth pattern. A pseudoinfiltrative pattern can occur when the glandular epithelium is entrapped within stromal fibrosis; however, the myoepithelial layer is retained. Occasionally, the glandular epithelium can grow in continuity with the surface squamous epithelium of the nipple, clinically simulating Paget disease of the breast.⁸ Immunohistochemical stains, specifically p63, p40, calponin 1, h-caldesmon, cytokeratin 5/6, CD10, and α; smooth muscle actin, highlight the myoepithelial cells, while cytokeratin 7 identifies the ductal epithelium, supporting the diagnosis.⁶ In addition to biopsy and microscopic tissue examination, touch preparation cytology, curettage cytology, and fine needle aspiration techniques have been used to perform cytologic examination of the lesions, aiding in identification of the benign or malignant nature of the neoplasm.⁶ Nipple adenoma also is referred to as florid papillomatosis of the nipple, papillary adenoma, erosive adenomatosis, and subareolar duct papillomatosis.⁷ 

Although nipple adenoma is a benign tumor, up to 16.5% of affected patients had an ipsilateral or contralateral mammary carcinoma.⁹ The majority arose coincidentally but separately in the same breast, and carcinoma arose directly from the nipple adenoma in 8 cases; 3 cases were carcinomas that arose in men.¹⁰ A definitive association or causal relationship between nipple adenoma and subsequent development of breast cancer has not been identified, and the incidence of nipple adenoma in patients with a positive family history of breast cancer has not been examined. Therefore, although various treatments including cryosurgery, nipple splitting enucleation, and Mohs micrographic surgery have been proposed, complete excision remains the gold standard of therapy. Regular breast examinations and digital mammography are necessary to screen for local recurrences.  

The Diagnosis: Phacomatosis Cesioflammea  

Phacomatosis pigmentovascularis (PPV) encompasses a group of diseases that have a vascular nevus coupled with a pigmented nevus.¹ It is divided into 5 types: Type I is defined by the presence of a vascular malformation and epidermal nevus; type II by a vascular malformation and dermal melanosis with or without nevus anemicus; type III by a vascular malformation and nevus spilus with or without nevus anemicus; type IV by a vascular malformation, dermal melanosis, and nevus spilus with or without nevus anemicus; and type V as cutis marmorata telangiectatica congenita and dermal melanosis.¹  

Happle² proposed a descriptive classification system in 2005 that eliminated type I PPV because neither linear epidermal nevus nor Becker nevus are derived from pigmentary cells. An appended "a" denotes a subtype with isolated cutaneous findings, while "b" is associated with extracutaneous manifestations. Phacomatosis cesioflammea (type IIa/b) refers to blue-hued dermal melanocytosis and nevus flammeus. Phacomatosis spilorosea (type IIIa/b) refers to nevus spilus and rose-colored nevus flammeus. Phacomatosis cesiomarmorata (type Va/b) refers to dermal melanocytosis and cutis marmorata telangiectasia congenita. The last group (type IVa/b) is unclassifiable phacomatosis pigmentovascularis.^2,3  

Phacomatosis pigmentovascularis can be isolated to the skin or have associated extracutaneous findings, including ocular melanocytosis, seizures, or cognitive delay due to intracerebral vascular malformations. Patients also can develop limb and soft-tissue overgrowth.⁴ Phacomatosis pigmentovascularis has been found to be associated with mutations in the GNA11 and GNAQ genes. The theory behind PPV is twin spotting, resulting from a somatic mutation that leads to mosaic proliferation of 2 different cell lines.⁵ Phacomatosis pigmentovascularis can occur in isolation or can demonstrate the phenotype of Sturge-Weber syndrome or Klippel-Trenaunay syndrome. In Sturge-Weber syndrome, capillary malformations involve the face and underlying leptomeninges and cerebral cortex. Glaucoma and epilepsy also may be present. In Klippel-Trenaunay syndrome, capillary malformations involve the extremities (usually the legs) in association with varicose veins, soft-tissue hypertrophy, and skeletal overgrowth.^6-9 Tuberous sclerosis is an autosomal-dominant neurocutaneous disease in which patients develop hamartomas throughout the body, including the brain, skin, eyes, kidneys, heart, and lungs. Cutaneous manifestations include facial angiofibromas, ungual fibromas, hypomelanotic macules (ash leaf spots, confetti-like lesions), shagreen patches or connective tissue hamartomas, and fibrous plaques on the forehead. Tuberous sclerosis does not include vascular malformations.¹⁰  

Our patient was diagnosed with PPV type IIb, or phacomatosis cesioflammea. He had a large port-wine stain involving the right upper arm, back (Figure, A), and chest (Figure, B) with involvement of the bilateral conjunctivae (Figure, C). Our case is unique because our patient did not have dermal melanocytosis, only ocular melanocytosis.  

Once underlying neurologic and vascular anomalies have been ruled out, port-wine stains can be treated cosmetically. Pulsed dye laser is the gold standard therapy for capillary malformations, especially when instituted early. Follow-up with ophthalmology is advised to monitor ocular involvement. Shields et al¹¹ suggested dilated fundoscopy for patients with port-wine stains because choroidal pigmentation often is the only ocular change seen. Ocular melanocytosis can progress to pigmented glaucoma or choroidal melanoma. 

The Diagnosis: Phacomatosis Cesioflammea  

Phacomatosis pigmentovascularis (PPV) encompasses a group of diseases that have a vascular nevus coupled with a pigmented nevus.¹ It is divided into 5 types: Type I is defined by the presence of a vascular malformation and epidermal nevus; type II by a vascular malformation and dermal melanosis with or without nevus anemicus; type III by a vascular malformation and nevus spilus with or without nevus anemicus; type IV by a vascular malformation, dermal melanosis, and nevus spilus with or without nevus anemicus; and type V as cutis marmorata telangiectatica congenita and dermal melanosis.¹  

Happle² proposed a descriptive classification system in 2005 that eliminated type I PPV because neither linear epidermal nevus nor Becker nevus are derived from pigmentary cells. An appended "a" denotes a subtype with isolated cutaneous findings, while "b" is associated with extracutaneous manifestations. Phacomatosis cesioflammea (type IIa/b) refers to blue-hued dermal melanocytosis and nevus flammeus. Phacomatosis spilorosea (type IIIa/b) refers to nevus spilus and rose-colored nevus flammeus. Phacomatosis cesiomarmorata (type Va/b) refers to dermal melanocytosis and cutis marmorata telangiectasia congenita. The last group (type IVa/b) is unclassifiable phacomatosis pigmentovascularis.^2,3  

Phacomatosis pigmentovascularis can be isolated to the skin or have associated extracutaneous findings, including ocular melanocytosis, seizures, or cognitive delay due to intracerebral vascular malformations. Patients also can develop limb and soft-tissue overgrowth.⁴ Phacomatosis pigmentovascularis has been found to be associated with mutations in the GNA11 and GNAQ genes. The theory behind PPV is twin spotting, resulting from a somatic mutation that leads to mosaic proliferation of 2 different cell lines.⁵ Phacomatosis pigmentovascularis can occur in isolation or can demonstrate the phenotype of Sturge-Weber syndrome or Klippel-Trenaunay syndrome. In Sturge-Weber syndrome, capillary malformations involve the face and underlying leptomeninges and cerebral cortex. Glaucoma and epilepsy also may be present. In Klippel-Trenaunay syndrome, capillary malformations involve the extremities (usually the legs) in association with varicose veins, soft-tissue hypertrophy, and skeletal overgrowth.^6-9 Tuberous sclerosis is an autosomal-dominant neurocutaneous disease in which patients develop hamartomas throughout the body, including the brain, skin, eyes, kidneys, heart, and lungs. Cutaneous manifestations include facial angiofibromas, ungual fibromas, hypomelanotic macules (ash leaf spots, confetti-like lesions), shagreen patches or connective tissue hamartomas, and fibrous plaques on the forehead. Tuberous sclerosis does not include vascular malformations.¹⁰  

Our patient was diagnosed with PPV type IIb, or phacomatosis cesioflammea. He had a large port-wine stain involving the right upper arm, back (Figure, A), and chest (Figure, B) with involvement of the bilateral conjunctivae (Figure, C). Our case is unique because our patient did not have dermal melanocytosis, only ocular melanocytosis.  

Once underlying neurologic and vascular anomalies have been ruled out, port-wine stains can be treated cosmetically. Pulsed dye laser is the gold standard therapy for capillary malformations, especially when instituted early. Follow-up with ophthalmology is advised to monitor ocular involvement. Shields et al¹¹ suggested dilated fundoscopy for patients with port-wine stains because choroidal pigmentation often is the only ocular change seen. Ocular melanocytosis can progress to pigmented glaucoma or choroidal melanoma. 

The Diagnosis: Phacomatosis Cesioflammea  

Phacomatosis pigmentovascularis (PPV) encompasses a group of diseases that have a vascular nevus coupled with a pigmented nevus.¹ It is divided into 5 types: Type I is defined by the presence of a vascular malformation and epidermal nevus; type II by a vascular malformation and dermal melanosis with or without nevus anemicus; type III by a vascular malformation and nevus spilus with or without nevus anemicus; type IV by a vascular malformation, dermal melanosis, and nevus spilus with or without nevus anemicus; and type V as cutis marmorata telangiectatica congenita and dermal melanosis.¹  

Happle² proposed a descriptive classification system in 2005 that eliminated type I PPV because neither linear epidermal nevus nor Becker nevus are derived from pigmentary cells. An appended "a" denotes a subtype with isolated cutaneous findings, while "b" is associated with extracutaneous manifestations. Phacomatosis cesioflammea (type IIa/b) refers to blue-hued dermal melanocytosis and nevus flammeus. Phacomatosis spilorosea (type IIIa/b) refers to nevus spilus and rose-colored nevus flammeus. Phacomatosis cesiomarmorata (type Va/b) refers to dermal melanocytosis and cutis marmorata telangiectasia congenita. The last group (type IVa/b) is unclassifiable phacomatosis pigmentovascularis.^2,3  

Phacomatosis pigmentovascularis can be isolated to the skin or have associated extracutaneous findings, including ocular melanocytosis, seizures, or cognitive delay due to intracerebral vascular malformations. Patients also can develop limb and soft-tissue overgrowth.⁴ Phacomatosis pigmentovascularis has been found to be associated with mutations in the GNA11 and GNAQ genes. The theory behind PPV is twin spotting, resulting from a somatic mutation that leads to mosaic proliferation of 2 different cell lines.⁵ Phacomatosis pigmentovascularis can occur in isolation or can demonstrate the phenotype of Sturge-Weber syndrome or Klippel-Trenaunay syndrome. In Sturge-Weber syndrome, capillary malformations involve the face and underlying leptomeninges and cerebral cortex. Glaucoma and epilepsy also may be present. In Klippel-Trenaunay syndrome, capillary malformations involve the extremities (usually the legs) in association with varicose veins, soft-tissue hypertrophy, and skeletal overgrowth.^6-9 Tuberous sclerosis is an autosomal-dominant neurocutaneous disease in which patients develop hamartomas throughout the body, including the brain, skin, eyes, kidneys, heart, and lungs. Cutaneous manifestations include facial angiofibromas, ungual fibromas, hypomelanotic macules (ash leaf spots, confetti-like lesions), shagreen patches or connective tissue hamartomas, and fibrous plaques on the forehead. Tuberous sclerosis does not include vascular malformations.¹⁰  

Our patient was diagnosed with PPV type IIb, or phacomatosis cesioflammea. He had a large port-wine stain involving the right upper arm, back (Figure, A), and chest (Figure, B) with involvement of the bilateral conjunctivae (Figure, C). Our case is unique because our patient did not have dermal melanocytosis, only ocular melanocytosis.  

Once underlying neurologic and vascular anomalies have been ruled out, port-wine stains can be treated cosmetically. Pulsed dye laser is the gold standard therapy for capillary malformations, especially when instituted early. Follow-up with ophthalmology is advised to monitor ocular involvement. Shields et al¹¹ suggested dilated fundoscopy for patients with port-wine stains because choroidal pigmentation often is the only ocular change seen. Ocular melanocytosis can progress to pigmented glaucoma or choroidal melanoma. 

The Diagnosis: Granulosis Rubra Nasi 

A history of prominent nasal sweating was later elicited and the patient was subsequently diagnosed with granulosis rubra nasi. She was instructed to continue daily use of topical pimecrolimus with the addition of topical atropine, resulting in complete resolution of the eruption at 6-week follow-up (Figure, A). She was then maintained on topical atropine monotherapy, only noting recurrence with cessation of the atropine (Figure, B).  

Other successful treatment regimens of granulosis rubra nasi include injection of botulinum toxin into the nose,¹ monotherapy with topical tacrolimus,² topical indomethacin, steroids, and cryotherapy, among other modalities.¹ Topical atropine and pimecrolimus were selected as first-line agents for treating our pediatric patient due to tolerability and their anti-inflammatory and anticholinergic properties.  

Granulosis rubra nasi is a form of focal hyperhidrosis that presents as erythematous papules, pustules, and vesicles of the midface, especially the nose.3 It is a fairly rare condition that can mimic many other common clinical entities, including comedonal acne, nevus comedonicus, periorificial dermatitis, and tinea faciei, but is resistant to treatments aimed at these disorders. It was first described as a "peculiar disease of the skin of the nose in children" in a case report by Jadassohn⁴ in 1901. It is most common in children aged 7 to 12 years and typically resolves at puberty; adults rarely are affected. Although the etiology has not yet been elucidated, autosomal-dominant transmission has been described, and the cutaneous changes are hypothesized to be secondary to hyperhidrosis.⁵ This postulation is further corroborated by a case report of a pheochromocytoma-associated granulosis rubra nasi that resolved with surgical excision of the pheochromocytoma.⁶ It is not uncommon for patients to have concomitant palmoplantar hyperhidrosis and acrocyanosis.⁵ Histopathologic examination is not necessary for diagnosis, but when performed, it discloses a mononuclear cellular infiltrate surrounding eccrine sweat ducts, blood vessels, and lymphatics without other abnormalities of the epidermis or pilosebaceous unit.^1-3,7 
 

The Diagnosis: Granulosis Rubra Nasi 

A history of prominent nasal sweating was later elicited and the patient was subsequently diagnosed with granulosis rubra nasi. She was instructed to continue daily use of topical pimecrolimus with the addition of topical atropine, resulting in complete resolution of the eruption at 6-week follow-up (Figure, A). She was then maintained on topical atropine monotherapy, only noting recurrence with cessation of the atropine (Figure, B).  

Other successful treatment regimens of granulosis rubra nasi include injection of botulinum toxin into the nose,¹ monotherapy with topical tacrolimus,² topical indomethacin, steroids, and cryotherapy, among other modalities.¹ Topical atropine and pimecrolimus were selected as first-line agents for treating our pediatric patient due to tolerability and their anti-inflammatory and anticholinergic properties.  

Granulosis rubra nasi is a form of focal hyperhidrosis that presents as erythematous papules, pustules, and vesicles of the midface, especially the nose.3 It is a fairly rare condition that can mimic many other common clinical entities, including comedonal acne, nevus comedonicus, periorificial dermatitis, and tinea faciei, but is resistant to treatments aimed at these disorders. It was first described as a "peculiar disease of the skin of the nose in children" in a case report by Jadassohn⁴ in 1901. It is most common in children aged 7 to 12 years and typically resolves at puberty; adults rarely are affected. Although the etiology has not yet been elucidated, autosomal-dominant transmission has been described, and the cutaneous changes are hypothesized to be secondary to hyperhidrosis.⁵ This postulation is further corroborated by a case report of a pheochromocytoma-associated granulosis rubra nasi that resolved with surgical excision of the pheochromocytoma.⁶ It is not uncommon for patients to have concomitant palmoplantar hyperhidrosis and acrocyanosis.⁵ Histopathologic examination is not necessary for diagnosis, but when performed, it discloses a mononuclear cellular infiltrate surrounding eccrine sweat ducts, blood vessels, and lymphatics without other abnormalities of the epidermis or pilosebaceous unit.^1-3,7 
 

The Diagnosis: Granulosis Rubra Nasi 

A history of prominent nasal sweating was later elicited and the patient was subsequently diagnosed with granulosis rubra nasi. She was instructed to continue daily use of topical pimecrolimus with the addition of topical atropine, resulting in complete resolution of the eruption at 6-week follow-up (Figure, A). She was then maintained on topical atropine monotherapy, only noting recurrence with cessation of the atropine (Figure, B).  

Other successful treatment regimens of granulosis rubra nasi include injection of botulinum toxin into the nose,¹ monotherapy with topical tacrolimus,² topical indomethacin, steroids, and cryotherapy, among other modalities.¹ Topical atropine and pimecrolimus were selected as first-line agents for treating our pediatric patient due to tolerability and their anti-inflammatory and anticholinergic properties.  

Granulosis rubra nasi is a form of focal hyperhidrosis that presents as erythematous papules, pustules, and vesicles of the midface, especially the nose.3 It is a fairly rare condition that can mimic many other common clinical entities, including comedonal acne, nevus comedonicus, periorificial dermatitis, and tinea faciei, but is resistant to treatments aimed at these disorders. It was first described as a "peculiar disease of the skin of the nose in children" in a case report by Jadassohn⁴ in 1901. It is most common in children aged 7 to 12 years and typically resolves at puberty; adults rarely are affected. Although the etiology has not yet been elucidated, autosomal-dominant transmission has been described, and the cutaneous changes are hypothesized to be secondary to hyperhidrosis.⁵ This postulation is further corroborated by a case report of a pheochromocytoma-associated granulosis rubra nasi that resolved with surgical excision of the pheochromocytoma.⁶ It is not uncommon for patients to have concomitant palmoplantar hyperhidrosis and acrocyanosis.⁵ Histopathologic examination is not necessary for diagnosis, but when performed, it discloses a mononuclear cellular infiltrate surrounding eccrine sweat ducts, blood vessels, and lymphatics without other abnormalities of the epidermis or pilosebaceous unit.^1-3,7 
 

The Diagnosis: Nodular Kaposi Sarcoma 

Epidemic Kaposi sarcoma (KS) primarily affects patients with human immunodeficiency virus (HIV) infection. Kaposi sarcoma can appear as brown, red, or blue-black macules, plaques, patches, nodules, or tumors, and it often is observed as multifocal cutaneous lesions located on the head, neck, and upper aspects of the trunk in a fulminant manner. Kaposi sarcoma portends a poor prognosis and is an AIDS-defining malignancy.^1-3 Importantly, antiretroviral therapy does not preclude its consideration in those without AIDS-defining CD4 cell counts and undetectable HIV viremia presenting with cutaneous manifestations.^2,3 A retrospective review by Daly et al⁴ reported KS lesions in patients with CD4 lymphocyte counts greater than 300 cells/µL, most of whom were antiretroviral therapy-naïve patients. Also, those with higher CD4 counts tended to have a solitary KS lesion at presentation, while those with CD4 counts less than 300 cells/µL tended to present with multiple foci.⁴ Epidemic KS lesions are clinically indistinguishable from other common cutaneous conditions in the differential diagnosis of KS, necessitating biopsy for histopathologic examination. Light microscopy findings help to delineate the diagnosis of KS. Immunohistochemical staining to the latent nuclear antigen 1 of human herpesvirus 8 (HHV-8) confirms the KS diagnosis.^5,6 Our patient's presentation as a solitary acral lesion was atypical for KS.  

Light microscopy of our patient's biopsy demonstrated a large tumor on the acral surface of the right hand. Dermal collections of basophilic spindled cells clustered with small slitlike vascular spaces with abundant erythrocyte extravasation and numerous large ectatic vessels at the periphery were seen (Figure, A). At higher magnification, interlaced bundles of spindle cells with slitlike vessels with scattered lymphocytes and plasma cells were seen (Figure, B). An immunohistochemical stain for HHV-8 was positive and largely confined to spindle cells (Figure, C). These findings confirmed KS and met AIDS-defining criteria. Awareness of these histopathologic features is key in differentiating KS from other conditions in the differential diagnosis.  

The patient's history of late latent syphilis coinfected with HIV and persistently elevated rapid plasma reagin that was recalcitrant to therapy placed an atypical nodular presentation within reason for the differential diagnosis. Deviations from the typical papulosquamous presentation with acral involvement in an immunocompromised patient mandates a consideration for syphilis with an atypical presentation. Atypical presentations include nodular, annular, pustular, lues maligna, frambesiform, corymbose, and photosensitive distributions.^7,8 Notably, coinfection with HIV modifies the clinical presentation, serology, and efficacy of treatment.^7-10 Atypical presentations are more common in coinfected HIV-positive patients, mandating a high degree of suspicion. Nodular secondary syphilis and the noduloulcerative form (lues maligna) often spare the palmar and plantar surfaces, and patients often have constitutional symptoms accompanying the cutaneous eruptions. In questionable cases, a biopsy lends clarification. Light microscopy on hematoxylin and eosin (H&E) staining may display acanthosis, superficial and deep perivascular swelling, plasma, histiocyte infiltrates, dermoepidermal junction changes, mixed patterns, epidermal hyperplasia, and dermal vascular thickening.^7-9,11 Spirochetes may be observed on Warthin-Starry stain; however, artifact obscuration from melanin granules and reticular fibers or paucity of organisms can make identification difficult. Immunohistochemical staining may prove useful when H&E stains are atypical or have a paucity of organisms or plasma cells or when silver stains have artifactual obscuration.⁹ Our patient's solitary palmar lesion without constitutional symptoms made an atypical nodular secondary syphilis presentation less likely. Ultimately, the histopathologic findings were consistent with KS.  

Bacillary angiomatosis (BA) is caused by Bartonella species and results in vascular proliferation with cutaneous manifestation. It frequently is observed in patients with HIV or other immunosuppressive conditions as well as patients with exposure to mammals or their vectors. Protean cutaneous manifestations and distributions of BA exist. The number of lesions can be singular to thousands. Solitary superficial pyogenic granuloma-like lesions can be clinically indistinguishable from both KS and pyogenic granuloma (PG). Superficial lesions often begin as red, violaceous, or flesh-colored papules that hemorrhage easily with trauma. The morphology of the papule can progress to be exophytic with dome-shaped or ulcerative surface features and is rubbery on palpation.¹² Biopsy is required to differentiate BA from KS. Bacillary angiomatosis on light microscopy with H&E shows protuberant, lobulated, round vessels with plump endothelial cells with or without necrosis. A neutrophil infiltrate in close proximity to bacilli may be noted. Warthin-Starry stain demonstrates numerous bacilli juxtaposed to these endothelial cells. The lack of immunohistochemical staining for HHV-8 also differentiates BA from KS.^12,13  

Pyogenic granuloma is resultant from proliferation of endothelial cells with a lobular architecture. Pyogenic granulomas are benign, rapidly progressive, acquired lesions presenting in the skin and mucous membranes. Pyogenic granuloma often presents as a single painless papule or nodule with a glistening red-violaceous color that occasionally appears with a perilesional collarette. The lesions are friable and easily hemorrhage. Pyogenic granuloma has been associated with local skin trauma and estrogen hormones. Histopathologic examination of PG assists with differentiation from other nodular lesions. Light microscopy with standard H&E staining demonstrates a network of capillaries arranged into a lobule surrounded by a fibrous matrix. Endothelial cells appear round and protrude into the vascular lamina. Mitotic activity is increased. Lack of findings on Warthin-Starry stain assists with differentiating PG from BA, while the microscopy architecture and immunohistochemical staining differentiates PG from KS.^6,13,14 

Squamous cell carcinoma (SCC) is the primary malignant cancer of the hand. The dorsal aspect of the hand is the most common location; SCC less commonly is located on the palmar surface, fingers, nail bed, or intertriginous areas.^15-17 Chakrabarti et al¹⁶ found that these lesions were invasive SCC when located on the palmar surface. Morphologically, SCC takes an exophytic papular, nodular, or scaly appearance with a red to flesh-colored appearance and poor demarcation of the borders. Progression to large ulcerated or secondarily infected lesions also can occur. The inflammatory reaction may cause tenderness to palpation and hemorrhage with trauma. Histopathologic examination of invasive SCC reveals atypical keratinocytes violating the basement membrane and abundant cytoplasm. Our patient's clinical presentation placed invasive SCC low on the differential diagnosis, and the histopathologic and immunohistochemical results eliminated SCC as the diagnosis. 

The Diagnosis: Nodular Kaposi Sarcoma 

Epidemic Kaposi sarcoma (KS) primarily affects patients with human immunodeficiency virus (HIV) infection. Kaposi sarcoma can appear as brown, red, or blue-black macules, plaques, patches, nodules, or tumors, and it often is observed as multifocal cutaneous lesions located on the head, neck, and upper aspects of the trunk in a fulminant manner. Kaposi sarcoma portends a poor prognosis and is an AIDS-defining malignancy.^1-3 Importantly, antiretroviral therapy does not preclude its consideration in those without AIDS-defining CD4 cell counts and undetectable HIV viremia presenting with cutaneous manifestations.^2,3 A retrospective review by Daly et al⁴ reported KS lesions in patients with CD4 lymphocyte counts greater than 300 cells/µL, most of whom were antiretroviral therapy-naïve patients. Also, those with higher CD4 counts tended to have a solitary KS lesion at presentation, while those with CD4 counts less than 300 cells/µL tended to present with multiple foci.⁴ Epidemic KS lesions are clinically indistinguishable from other common cutaneous conditions in the differential diagnosis of KS, necessitating biopsy for histopathologic examination. Light microscopy findings help to delineate the diagnosis of KS. Immunohistochemical staining to the latent nuclear antigen 1 of human herpesvirus 8 (HHV-8) confirms the KS diagnosis.^5,6 Our patient's presentation as a solitary acral lesion was atypical for KS.  

Light microscopy of our patient's biopsy demonstrated a large tumor on the acral surface of the right hand. Dermal collections of basophilic spindled cells clustered with small slitlike vascular spaces with abundant erythrocyte extravasation and numerous large ectatic vessels at the periphery were seen (Figure, A). At higher magnification, interlaced bundles of spindle cells with slitlike vessels with scattered lymphocytes and plasma cells were seen (Figure, B). An immunohistochemical stain for HHV-8 was positive and largely confined to spindle cells (Figure, C). These findings confirmed KS and met AIDS-defining criteria. Awareness of these histopathologic features is key in differentiating KS from other conditions in the differential diagnosis.  

The patient's history of late latent syphilis coinfected with HIV and persistently elevated rapid plasma reagin that was recalcitrant to therapy placed an atypical nodular presentation within reason for the differential diagnosis. Deviations from the typical papulosquamous presentation with acral involvement in an immunocompromised patient mandates a consideration for syphilis with an atypical presentation. Atypical presentations include nodular, annular, pustular, lues maligna, frambesiform, corymbose, and photosensitive distributions.^7,8 Notably, coinfection with HIV modifies the clinical presentation, serology, and efficacy of treatment.^7-10 Atypical presentations are more common in coinfected HIV-positive patients, mandating a high degree of suspicion. Nodular secondary syphilis and the noduloulcerative form (lues maligna) often spare the palmar and plantar surfaces, and patients often have constitutional symptoms accompanying the cutaneous eruptions. In questionable cases, a biopsy lends clarification. Light microscopy on hematoxylin and eosin (H&E) staining may display acanthosis, superficial and deep perivascular swelling, plasma, histiocyte infiltrates, dermoepidermal junction changes, mixed patterns, epidermal hyperplasia, and dermal vascular thickening.^7-9,11 Spirochetes may be observed on Warthin-Starry stain; however, artifact obscuration from melanin granules and reticular fibers or paucity of organisms can make identification difficult. Immunohistochemical staining may prove useful when H&E stains are atypical or have a paucity of organisms or plasma cells or when silver stains have artifactual obscuration.⁹ Our patient's solitary palmar lesion without constitutional symptoms made an atypical nodular secondary syphilis presentation less likely. Ultimately, the histopathologic findings were consistent with KS.  

Bacillary angiomatosis (BA) is caused by Bartonella species and results in vascular proliferation with cutaneous manifestation. It frequently is observed in patients with HIV or other immunosuppressive conditions as well as patients with exposure to mammals or their vectors. Protean cutaneous manifestations and distributions of BA exist. The number of lesions can be singular to thousands. Solitary superficial pyogenic granuloma-like lesions can be clinically indistinguishable from both KS and pyogenic granuloma (PG). Superficial lesions often begin as red, violaceous, or flesh-colored papules that hemorrhage easily with trauma. The morphology of the papule can progress to be exophytic with dome-shaped or ulcerative surface features and is rubbery on palpation.¹² Biopsy is required to differentiate BA from KS. Bacillary angiomatosis on light microscopy with H&E shows protuberant, lobulated, round vessels with plump endothelial cells with or without necrosis. A neutrophil infiltrate in close proximity to bacilli may be noted. Warthin-Starry stain demonstrates numerous bacilli juxtaposed to these endothelial cells. The lack of immunohistochemical staining for HHV-8 also differentiates BA from KS.^12,13  

Pyogenic granuloma is resultant from proliferation of endothelial cells with a lobular architecture. Pyogenic granulomas are benign, rapidly progressive, acquired lesions presenting in the skin and mucous membranes. Pyogenic granuloma often presents as a single painless papule or nodule with a glistening red-violaceous color that occasionally appears with a perilesional collarette. The lesions are friable and easily hemorrhage. Pyogenic granuloma has been associated with local skin trauma and estrogen hormones. Histopathologic examination of PG assists with differentiation from other nodular lesions. Light microscopy with standard H&E staining demonstrates a network of capillaries arranged into a lobule surrounded by a fibrous matrix. Endothelial cells appear round and protrude into the vascular lamina. Mitotic activity is increased. Lack of findings on Warthin-Starry stain assists with differentiating PG from BA, while the microscopy architecture and immunohistochemical staining differentiates PG from KS.^6,13,14 

Squamous cell carcinoma (SCC) is the primary malignant cancer of the hand. The dorsal aspect of the hand is the most common location; SCC less commonly is located on the palmar surface, fingers, nail bed, or intertriginous areas.^15-17 Chakrabarti et al¹⁶ found that these lesions were invasive SCC when located on the palmar surface. Morphologically, SCC takes an exophytic papular, nodular, or scaly appearance with a red to flesh-colored appearance and poor demarcation of the borders. Progression to large ulcerated or secondarily infected lesions also can occur. The inflammatory reaction may cause tenderness to palpation and hemorrhage with trauma. Histopathologic examination of invasive SCC reveals atypical keratinocytes violating the basement membrane and abundant cytoplasm. Our patient's clinical presentation placed invasive SCC low on the differential diagnosis, and the histopathologic and immunohistochemical results eliminated SCC as the diagnosis. 

The Diagnosis: Nodular Kaposi Sarcoma 

Epidemic Kaposi sarcoma (KS) primarily affects patients with human immunodeficiency virus (HIV) infection. Kaposi sarcoma can appear as brown, red, or blue-black macules, plaques, patches, nodules, or tumors, and it often is observed as multifocal cutaneous lesions located on the head, neck, and upper aspects of the trunk in a fulminant manner. Kaposi sarcoma portends a poor prognosis and is an AIDS-defining malignancy.^1-3 Importantly, antiretroviral therapy does not preclude its consideration in those without AIDS-defining CD4 cell counts and undetectable HIV viremia presenting with cutaneous manifestations.^2,3 A retrospective review by Daly et al⁴ reported KS lesions in patients with CD4 lymphocyte counts greater than 300 cells/µL, most of whom were antiretroviral therapy-naïve patients. Also, those with higher CD4 counts tended to have a solitary KS lesion at presentation, while those with CD4 counts less than 300 cells/µL tended to present with multiple foci.⁴ Epidemic KS lesions are clinically indistinguishable from other common cutaneous conditions in the differential diagnosis of KS, necessitating biopsy for histopathologic examination. Light microscopy findings help to delineate the diagnosis of KS. Immunohistochemical staining to the latent nuclear antigen 1 of human herpesvirus 8 (HHV-8) confirms the KS diagnosis.^5,6 Our patient's presentation as a solitary acral lesion was atypical for KS.  

Light microscopy of our patient's biopsy demonstrated a large tumor on the acral surface of the right hand. Dermal collections of basophilic spindled cells clustered with small slitlike vascular spaces with abundant erythrocyte extravasation and numerous large ectatic vessels at the periphery were seen (Figure, A). At higher magnification, interlaced bundles of spindle cells with slitlike vessels with scattered lymphocytes and plasma cells were seen (Figure, B). An immunohistochemical stain for HHV-8 was positive and largely confined to spindle cells (Figure, C). These findings confirmed KS and met AIDS-defining criteria. Awareness of these histopathologic features is key in differentiating KS from other conditions in the differential diagnosis.  

The patient's history of late latent syphilis coinfected with HIV and persistently elevated rapid plasma reagin that was recalcitrant to therapy placed an atypical nodular presentation within reason for the differential diagnosis. Deviations from the typical papulosquamous presentation with acral involvement in an immunocompromised patient mandates a consideration for syphilis with an atypical presentation. Atypical presentations include nodular, annular, pustular, lues maligna, frambesiform, corymbose, and photosensitive distributions.^7,8 Notably, coinfection with HIV modifies the clinical presentation, serology, and efficacy of treatment.^7-10 Atypical presentations are more common in coinfected HIV-positive patients, mandating a high degree of suspicion. Nodular secondary syphilis and the noduloulcerative form (lues maligna) often spare the palmar and plantar surfaces, and patients often have constitutional symptoms accompanying the cutaneous eruptions. In questionable cases, a biopsy lends clarification. Light microscopy on hematoxylin and eosin (H&E) staining may display acanthosis, superficial and deep perivascular swelling, plasma, histiocyte infiltrates, dermoepidermal junction changes, mixed patterns, epidermal hyperplasia, and dermal vascular thickening.^7-9,11 Spirochetes may be observed on Warthin-Starry stain; however, artifact obscuration from melanin granules and reticular fibers or paucity of organisms can make identification difficult. Immunohistochemical staining may prove useful when H&E stains are atypical or have a paucity of organisms or plasma cells or when silver stains have artifactual obscuration.⁹ Our patient's solitary palmar lesion without constitutional symptoms made an atypical nodular secondary syphilis presentation less likely. Ultimately, the histopathologic findings were consistent with KS.  

Bacillary angiomatosis (BA) is caused by Bartonella species and results in vascular proliferation with cutaneous manifestation. It frequently is observed in patients with HIV or other immunosuppressive conditions as well as patients with exposure to mammals or their vectors. Protean cutaneous manifestations and distributions of BA exist. The number of lesions can be singular to thousands. Solitary superficial pyogenic granuloma-like lesions can be clinically indistinguishable from both KS and pyogenic granuloma (PG). Superficial lesions often begin as red, violaceous, or flesh-colored papules that hemorrhage easily with trauma. The morphology of the papule can progress to be exophytic with dome-shaped or ulcerative surface features and is rubbery on palpation.¹² Biopsy is required to differentiate BA from KS. Bacillary angiomatosis on light microscopy with H&E shows protuberant, lobulated, round vessels with plump endothelial cells with or without necrosis. A neutrophil infiltrate in close proximity to bacilli may be noted. Warthin-Starry stain demonstrates numerous bacilli juxtaposed to these endothelial cells. The lack of immunohistochemical staining for HHV-8 also differentiates BA from KS.^12,13  

Pyogenic granuloma is resultant from proliferation of endothelial cells with a lobular architecture. Pyogenic granulomas are benign, rapidly progressive, acquired lesions presenting in the skin and mucous membranes. Pyogenic granuloma often presents as a single painless papule or nodule with a glistening red-violaceous color that occasionally appears with a perilesional collarette. The lesions are friable and easily hemorrhage. Pyogenic granuloma has been associated with local skin trauma and estrogen hormones. Histopathologic examination of PG assists with differentiation from other nodular lesions. Light microscopy with standard H&E staining demonstrates a network of capillaries arranged into a lobule surrounded by a fibrous matrix. Endothelial cells appear round and protrude into the vascular lamina. Mitotic activity is increased. Lack of findings on Warthin-Starry stain assists with differentiating PG from BA, while the microscopy architecture and immunohistochemical staining differentiates PG from KS.^6,13,14 

Squamous cell carcinoma (SCC) is the primary malignant cancer of the hand. The dorsal aspect of the hand is the most common location; SCC less commonly is located on the palmar surface, fingers, nail bed, or intertriginous areas.^15-17 Chakrabarti et al¹⁶ found that these lesions were invasive SCC when located on the palmar surface. Morphologically, SCC takes an exophytic papular, nodular, or scaly appearance with a red to flesh-colored appearance and poor demarcation of the borders. Progression to large ulcerated or secondarily infected lesions also can occur. The inflammatory reaction may cause tenderness to palpation and hemorrhage with trauma. Histopathologic examination of invasive SCC reveals atypical keratinocytes violating the basement membrane and abundant cytoplasm. Our patient's clinical presentation placed invasive SCC low on the differential diagnosis, and the histopathologic and immunohistochemical results eliminated SCC as the diagnosis.