Unilateral dermatomal cavernous hemangiomatosis (UDCH) is a nosologic entity characterized by (1) multiple hemangiomata; (2) location in lower dermis and subcutaneous tissue; (3) unilateral dermatomal distribution; (4) lack of gastrointestinal lesions; (5) lack of enchondromata; (6) benign course; (7) absence of family history; (8) onset either acquired or congenital, and (9) changes in size possibly hormonal in nature. UDCH must be distinguished from other disorders with multiple hemangiomata which convey adverse prognoses.