Benign proliferative myositis of the sternohyoid muscle: review and case report.

We report a case of a 51-year-old woman who presented with a rapidly enlarging, painful, midline neck mass that developed over a three day period. A CT scan of the neck showed a solid circumscribed mass in the sternohyoid muscle. The initial differential diagnosis included inflammation of thyroglossal duct remnant, an abnormal lymph node, and thyroid carcinoma. The patient underwent operative excision with final pathology revealing proliferative myositis. Proliferative myositis is an uncommon benign proliferation of skeletal muscle and has only been reported a limited number of times in the head and neck region.