Infiltrative intramuscular myxoma of the cervical spine: a case report.

Background Context: Myxomas are benign tumors of mesenchymal cell origin that usually present as solitary lesions. They are infrequently associated with fibrous dysplasia, as in McCune-Albright or Mazabraud syndrome. Myxomas can develop in a variety of locations, although the most frequent sites are the thigh, buttocks, shoulder, and upper arm. Intramuscular myxomas (IMs) refer to lesions that occur within muscle compartments. They have been infrequently reported in the neck musculature.

Purpose: To date, only five cases have been reported within the posterior neck muscles without associated intraspinal extension. To our knowledge, this is the first case of an IM presenting with extension into the spinal canal.

Study Design: We report a case of posterior cervical IM with intraspinal extension presenting in a 63-year-old woman as a palpable mass.

Methods: Complete intralesional resection of the tumor was achieved by standard midline posterior approach. Meticulous resection of the entire capsule was achieved and all margins were confirmed to be free of neoplasm.

Results: A diagnosis of myxoma was provided on pathologic evaluation. Follow-up at 1.5 years confirmed maintained complete resolution of the preoperative symptoms, with no evidence of local recurrence on imaging.

Conclusions: Intramuscular myxomas should be included in the differential diagnosis of cervical paraspinal tumors. Furthermore, we suggest that masses involving the axial muscles should be closely monitored and the patient counseled regarding potential neurologic sequelae.