[Non-traumatic myositis ossificans. Ultrasonic and x-ray computed tomographic aspects. Apropos of a case]

Radiology in a patient with non-traumatic myositis ossificans produced standard images suggestive of juxta-cortical osteosarcoma, the peripheral form of a chondrosarcoma or a synovial sarcoma. Ultrasound failed to provide a conclusive diagnosis, and a scan was the only means of suggesting the benign nature of the lesion by demonstrating integrity of bony cortex and characteristic disposition of calcifications.