Myositis ossificans in a child athlete: a case study.

Background: A 13-year-old female athlete presented with a painful lesion in her right buttock for which she had been receiving physiotherapy. It was keeping her from participating in sports.

Aim: To report on a case of traumatic myositis ossificans in a child athlete - including the presentation, investigations, management, and outcome.

Findings: Palpation of the right buttock indicated a tender mass. Investigation by musculoskeletal ultrasound detected a large hypoechoic lesion. An MRI revealed patterns of calcification that were inconclusive in differentiating between a malignant or benign lesion. Macroscopic and microscopic histological examination, as well as immunohistochemistry, were consistent with myositis ossificans (MO), a non-malignant condition. The patient improved remarkably within three months of treatment with rest, non-steroidal anti-inflammatory drugs (NSAIDs) and extracorporeal shock wave therapy (ESWT).

Implications: Accurate differentiation of myositis ossificans from other benign and malignant soft tissue lesions may require histological evaluation in addition to a comprehensive radiological workup. Successful treatment with the patient being able to return to a pain-free and active state is achievable. Extracorporeal shock-wave therapy can play an important role in the management of this condition and should be considered when presented with a case of MO.