Myositis ossificans circumscripta of the thigh: A pediatric case report.

Circumscribed myositis ossificans is a benign process of focal heterotopic ossification of the soft tissues, occurring in young subjects, usually following trauma. We report a case of a 15-year-old patient who suffered a direct trauma to the thigh during a soccer match, and developed a hard mass in the anterior face of the thigh. The patient was diagnosed with myositis ossificans secondary to trauma. In this case report, we want to illustrate the different imaging aspects of this benign condition, both in conventional radiology, computed tomography and magnetic resonance imaging, as its clinical and radiological appearance can be misleading, suggesting a sarcomatous neoplastic process.