A Case Report of Proliferative Myositis of Bilateral Sternocleidomastoid Muscles.

A case of prolif erative myositis of the bilateral sternocleidomastoid muscle in a 64-year old woman is reported. The patient visited our clinic, complaining of a sore throat and cervical pain, with strong limitation of neck movement, especially backward movement. Physical examination revealed hardness along the bilateral sternocleidomastoid muscles. CT, MRI and Echo imaging studies suggested the presence of pathological lesions in the muscles. Immunochemical examination showed a high level of muscle emzymes, suggesting myositis. The histopathological diagnosis of the excised tissue was proliferative myositis. This disease is a very rare condition, and no case of bilateral myositis has been previously reported in the Japanese literature. We discussed this disease from a clinicopathological viewpoint.