Widespread porokeratotic adnexal ostial nevus: clinical features and proposal of a new name unifying porokeratotic eccrine ostial and dermal duct nevus and porokeratotic eccrine and hair follicle nevus.

Porokeratotic eccrine ostial and dermal duct nevus and a similar condition, porokeratotic eccrine and hair follicle nevus, are rare disorders of keratinization with eccrine and hair follicle involvement. We describe the clinical features in 5 patients, all of whom had widespread skin involvement following the lines of Blaschko. Two patients presented with erosions in the newborn period as the initial manifestation of their disease; one had an associated structural anomaly, unilateral breast hypoplasia; and one adult had malignant transformation in the nevus with development of multifocal squamous cell carcinomas.

Cutaneous involvement by angioimmunoblastic T-cell lymphoma: a unique histologic presentation, mimicking an infectious etiology.

Angioimmunoblastic T-cell lymphoma (AILT) is an aggressive peripheral T-cell lymphoma that is frequently accompanied by a cutaneous eruption. The cutaneous findings most commonly consist of a maculopapular eruption on the trunk. However, purpura, infiltrated or urticarial plaques, papulovesicular lesions, nodules, and erythroderma have also been reported.

Cutaneous plasmacytosis: A report of five cases with immunohistochemical evaluation for HHV-8 expression.

Cutaneous plasmacytosis is a rare disorder that typically affects middle-aged to older individuals of Asian, particularly Japanese, descent. Clinically, it is characterized by multiple asymptomatic red-brown plaques and nodules on the trunk. Lymphadenopathy and hypergammaglobulinemia may be present.

Keratosis lichenoides chronica mimicking verrucous secondary syphilis.

Keratosis lichenoides chronica is a rare dermatosis of unknown etiology with a wide variety of cutaneous manifestations. We present a 47-year-old male with a history of progressive and recalcitrant hyperkeratotic and warty plaques, mimicking verrucous secondary syphilis both clinically and microscopically. We review the clinical manifestations, microscopic features, and treatment modalities for this rare and distinctive dermatosis.