Intramuscular Hemangioma of the Sternocleidomastoid: A Rare Tumor in an Unusual Location.

Intramuscular hemangiomas (IMH) are benign vascular tumors of the skeletal muscles. These tumors are uncommon in the head and neck region and usually affect the trunk and extremities. IMH of the masseter and trapezius muscles have been reported in the head and neck region. However, the sternocleidomastoid is extremely rare. In the current case report, we described a 25-year-old man with a rare case of intramuscular hemangioma involving the sternocleidomastoid muscle and reviewed the relevant literature. Contrast-enhanced computed tomography was initially obtained and showed a slightly hyperdense soft tissue mass. Head and neck magnetic resonance imaging (MRI) demonstrate a well-delineated hyperintense lesion on the T2 sequence suggestive of a soft tissue hemangioma. Subsequently, angioembolization using onyx was performed, followed by surgical excision of the mass under general anesthesia. Histopathological examination of the mass showed vascular proliferation within the skeletal muscles, and fatty tissue with an abundance of capillaries, which are consistent with capillary type intramuscular hemangioma. The patient was followed up in the clinic until the wound healed. Three months after surgery, no recurrence was observed. Preoperative angioembolization contributed to the success of IMH surgery by reducing morbidity, facilitating complete excision, and decreasing the risk of recurrence.