Intramuscular hemangioma. Report of a case.

Intramuscular hemangiomas are rare tumors. Their occurrence in the head and neck region is even more unusual. The first reported case involving the orbicularis oris muscle is presented. The histologic classification is that of the mixed-vessel type, which occurs in the head and neck region only 5 percent of the time. Included is a review of the literature, with a discussion of the current philosophy of etiology, diagnosis, and treatment. Knowledge of this type of tumor is important to the oral and maxillofacial surgeon who evaluates mass lesions.