[Tufted hemangioma. Clinicopathologic and immunohistologic analysis of 5 cases of a distinct entity within the spectrum of capillary hemangioma].

Two female and three male patients with acquired "tufted angioma" are presented. The age of these patients ranged from 10 to 62 years. Two lesions were sited in the head and neck region, two in the upper extremities, and one on the trunk. Clinically, the angiomatous lesions appeared as elevated plaques, flat lesions with papular and macular areas, or erythematous plaques with small nodules. In four cases a biopsy was done, and in one case the tumour was excised. Histologically, the neoplasms were characterized by irregularly distributed vascular tufts in the dermis, and, in one case, in the upper subcutis. The vascular tufts were composed of plump endothelial cells and spindle-shaped pericytes surrounded by crescent-shaped vascular spaces. The positive staining for CD 31 and for CD 34 and alpha-smooth muscle actin, and the negative staining of endothelial cells for factor VIII underline both the existence of two cellular components in tufted angioma and the immaturity of endothelial cells. Evidence of regular mitotic figures in two cases and increased proliferative activity in three out of four cases tested, emphasize the neoplastic nature of slowly growing tufted angioma. Benign tufted angioma is a distinct entity in the spectrum of capillary haemangiomas and must be distinguished from other vascular neoplasms.