Myositis ossificans in the paraspinal muscles of the neck after acupuncture: a case report

Abstract Background context Although traumatic myositis ossificans (MO) has been reported occasionally, MO of paraspinal muscles has been rarely seen in the cervical spine after minor injury. This is difficult to distinguish from benign and malignant soft lesions in cases of a lack of definite trauma history. Purpose We report a case of MO in the cervical paraspinal muscle after acupuncture and describe methods for diagnosis and proper treatment, including classification, etiology, and radiologic and histologic features. Study design Case report. Methods A 26-year-old woman complained of posterior neck pain that had began 2 months earlier and neck swelling after acupuncture. No abnormal finding existed on the X-ray except soft tissue swelling. Magnetic resonance imaging was evaluated because of constant neck pain. To obtain more accurate assessment, computed tomography-guided biopsy was performed and a diagnosis of MO was made. Results The patient was conservatively treated through rest and analgesics. Posterior neck pain and swelling improved for a several months. The hyperdensity was comparable with the bony density, and the size of the calcified lesion on X-ray diminished until the last follow-up. Conclusions Myositis ossificans that can occur after acupuncture should be recognized as a possible cause of persistent neck pain and swelling despite no definite trauma after thorough evaluation of the neoplasm and infection.