Intramuscular hemangioma of the retropharyngeal space

Intramuscular hemangioma (IMH) is a distinctive type of hemangioma occurring within skeletal muscle. Most IMH are located in the lower extremity, particularly in the muscles of the thigh. When present in the head and neck region, the masseter and trapezius muscle are the most frequently involved sites.

We reported a case of unusual localization of the head and neck IMH occurring within the retropharyngeal space (RPS). To our knowledge, this is the second such case reported in the English literature. The tumor presented as a left-sided neck mass with bulging of the posterior and left lateral oropharyngeal wall on indirect laryngoscopy. Computed tomography (CT) scan revealed an ill-defined mass in the RPS at the oropharyngeal level. The lesion was excised via a transoral approach and microscopically diagnosed as IMH, the complex malformation subtype. Although surgical margins were positive, no recurrence of the tumor was noted in the 17-month follow-up.

Intramuscular hemangioma should be considered in the differential diagnosis of deep head and neck masses. The knowledge of the infiltrative nature and recurrence rate of an IMH is useful for appropriate managment.