Bacillary angiomatosis presenting as a soft-tissue tumor without skin involvement.

A patient with human immunodeficiency virus infection presented with a soft-tissue mass which histologically and clinically mimicked an angiosarcoma. Ultrastructural study, however, revealed bacteria identical to those seen in cutaneous bacillary angiomatosis, but the patient had no skin lesions. To our knowledge, this represents the first report of soft tissue involvement by bacillary angiomatosis without the presence of skin lesions.