Verrucous cutaneous sarcoidosis: case report and review of this unusual variant of cutaneous sarcoidosis.

Sarcoidosis is a multisystem disorder of unknown origin, characterized by the accumulation of lymphocytes and mononuclear histiocytes inducing the formation of noncaseating "naked" epithelioid granulomas. The lungs, lymphatic system, and skin are most often affected, but sarcoidosis may affect any organ. Cutaneous involvement of sarcoidosis is often the sentinel sign of the disease, with the skin sometimes being exclusively affected. We present a case of a 54-year-old African American woman with long-standing history of pulmonary sarcoidosis that presented with multiple verrucous cutaneous lesions on the upper and lower extremities mimicking carcinoma. The initial cutaneous biopsy was superficial in nature, and the pathologist raised the consideration of a possible keratoacanthoma. A deeper skin shave biopsy was performed, and the histopathology showed verrucous pseudoepitheliomatous epidermal hyperplasia with scattered noncaseating granulomas in the superficial dermis. Stains (acid-fast bacillus, Periodic acid-Schiff, and Gomori-Grocott methenamine silver stains) were negative for microorganisms. Given the clinical setting and histomorphology of the cutaneous lesions, the diagnosis of verrucous sarcoidosis was rendered. Verrucous sarcoidosis is a rare cutaneous manifestation of sarcoidosis that could be easily misdiagnosed if it is not appropriately biopsied. This hinders the precise evaluation of the histological specimen, overall clinical picture, and administration of appropriate therapy.