[Asymptomatic digital angioleiomyoma].

Angioleiomyomas that present with no symptoms are extremely rare, except when located on the head and neck. 1 Three cutaneous variants of this tumor have been described: piloleiomyoma, which originates in the erector pili muscle; angioleiomyoma, which originates in the smooth muscle of blood vessel walls; and genital leiomyoma, which originates in the smooth muscle of the scrotum, vulva, or nipple. An 18-year-old man presented with a mass from 7 years earlier, located on the third finger of his left hand. The lesion was supple, flesh-colored, and nodular, with an approximate diameter of 1.5 cm (Figure 1A). The skin surface was smooth and the tumor was not attached to deep tissues. Under local anesthesia, the lesion was removed and the tumor-feeding vessels were ligated (Figure 1B). A histopathological study with hematoxylin-eosin showed that the lesion was a regular, well-delimited neoplasm. It was well vascularized with thick vascular walls and bundles of intervascular smooth muscle fibers (Figure 2). The cells in smooth muscle bundles had an elongated nucleus, of rounded, cigar-shaped borders and abundant eosinophilic cytoplasm. All findings were consistent with the diagnosis of angioleiomyoma. Vascular leiomyomas are solitary benign tumors originating in the smooth muscle layer of the vessel walls. 5 However, some authors believe this entity could be a type of hamartoma, vascular malformation, or a stage within the continuous process of smooth muscle proliferation in the context of transformation of the hemangiomas to leiomyomas. 6-8 On occasions, special stains for smooth muscle cells (Masson trichrome and immunohistochemical techniques for smooth muscle vimentin, desmin, and actin) may be needed to 292 differentiate angioleiomyomas from other tumors. Hachisuga et al 7 have classified angioleiomyomas into 3 histological types: solid, in which the muscle bundles surround numerous small vascular lumens; cavernous, with dilated vascular channels, in which the vascular walls are difficult to distinguish from the intervascular smooth muscle; and venous, with thick vascular walls, readily distinguishable from intervascular smooth muscle. Angioleiomyomas are more common between the third and fifth decade of life and are twice as common among women as men. 9 Our patient's lesion is atypical because there were no symptoms and because of its location (proximal phalanx of the third finger on the left hand). This type of lesion appears predominantly on the limbs, particularly the legs, but may also be found on any other part of the body such as the arms, trunk, head, and neck. 10 …