A rare cause of painful cervical swelling: myositis ossificans progressiva in childhood. Report of a case.

Myositis ossificans progressiva (MOP) is a rare condition of which we report a case in a 13-year-old girl with involvement of the cervical paraspinal and periscapular muscles. No ectopic ossifications were visible on plain radiographs. Computed tomography disclosed diffuse inflammation. Plain radiographs of the toes confirmed the diagnosis by visualizing characteristic bone abnormalities. Knowledge of the digital abnormalities seen in MOP is important to avoid unnecessary diagnostic investigations, most notably a surgical biopsy, which may trigger a flare of the disease. The prognosis is guarded.