Ultrastructural investigation on cutaneous angioleiomyoma.

Electron-microscopic examination of a cutaneous angioleiomyoma demonstrated that the muscular coat enveloping the blood vessels is formed of typical smooth muscle cells. The central vessels exhibit the ultrastructural features of small venules with a prominent endothelium and large numbers of Weibel-Palade bodies. Except for scanty unmyelinated nerve fibers accompanying small arterioles, no significant nerval structures were encountered. In view of the evident ultrastructural differences, a relationship of angioleiomyoma and glomus tumor can be ruled out.