[Reactive angioendotheliomatosis--a rare disease mimicking Kaposi sarcoma: a case report].

Reactive angioendotheliomatosis (RAE) is a rare disorder with clinical presentation of multiple cutaneous lesions. RAE mimics mainly Kaposi sarcoma (KS) and, rarely angiosarcoma, and it usually arises in association with other systemic disease. The associated disease is mostly chronic infection. RAE presents diagnostic problems for both the clinician and pathologist. We present RAE in a 46-year-old male patient with a history of alcoholism and pulmonary tuberculosis. Multiple, rapidly progressive, itching and burning, and focally confluent cutaneous erythematous and purple macules, plaques and nodules of various size and wide distribution appeared during a course of antituberculotic therapy. The suggested clinical diagnosis was KS. The lesions were repeatedly evaluated by biopsy. Histologically, there were poorly marginated proliferations of capillaries in the dermis which extended focally into the subcutaneous tissue. Associated erythrocyte extravasations, stromal hemosiderin depositions and mild chronic inflammatory infiltrates were also present in the lesion. Adnexal and neuronal extension of the lesional vessels was an intriguing finding, not described in the literature until now. The microscopical findings were interpreted by surgical pathologists as capillary hemangioma and as "angioblastoma of Nakagawa" (one and two times, respectively).