Congenital multiple plaquelike glomus tumors.

We encountered two patients with congenital multiple plaquelike glomus tumors. These lesions were present at birth and enlarged with body growth, attaining a diameter of up to 13 cm. The diagnosis was confirmed by histologic and electron-microscopic examination, which revealed the typical changes of glomus tumors. Immunocytochemistry findings demonstrated the tumor cells to be vimentin- and alpha-smooth muscle-actin-positive and desmin-negative. On ultrastructural examination, typical dense bodies and attachment plaques were easily found within the tumor cells. Glomus cells were coated by a thick basal lamina.