Intramuscular hemangioma of the masseter muscle: its characteristic appearance on magnetic resonance imaging.

A 10-year-old girl presented with a 6-month history of right facial swelling. Magnetic resonance imaging (MRI) revealed a tumor in the masseter muscle. On exploration through a preauricular incision, a vascular mass was found located in the lateral aspect of the right masseter muscle. The characteristic MRI appearance of the intramuscular hemangioma of the masseter muscle is shown and the value of MRI for a preoperative differential diagnosis is discussed.