Intramuscular hemangioma in the head and neck.

Intramuscular hemangioma is a distinct type of hemangioma occurring within skeletal muscle and making up less than one per cent of all hemangiomas. They occur most often in the trunk and extremities, perhaps beacuse of the larger muscle volume in thos areas. 13.5 per cent of intramuscular hemangiomas do occur in the head and neck region and for this reason they should be considered in the differential diagnosis of head and neck masses. The first case of an intramuscular hemangioma of the digastric muscle is presented and confirmed by electron microscopic sections. An interesting finding in this tumor is the proliferation of both endothelial cells and pericytes. Hemangiomas are classified according to vessel size; "large vessel" cavernous, "small vessel" capillary, and "mixed". Various etiologies and modalities of treatment are discussed, and total excision with ligation of the feeding vessels is advocated to prevent the high incidence of later recurrence.