Histochemical evidence of adenosine triphosphatase activity in glomus tumor--report of a case.

A case of glomus tumor was studied by light and electron microscopic enzyme histochemistry. Histologically, this case was classified as glomangioma or vascular form of glomus tumor. The tumor cells had ultrastructural characteristics of smooth muscle cells such as large amount of thin filaments with dense bodies, basal lamina and numerous pinocytotic vesicles. Among the 3 membrane associated enzymes, namely alkaline phosphatase, adenosine triphosphatase (ATPase) and 5'nucleotidase, only ATPase was detectable in the cell membrane and pinocytotic vesicles. It is suggested that the ATPase activity of the tumor cells shows additional evidence of smooth muscle character of glomus tumor.