Figure 12.

A 22-year-old male with left shoulder pain after trauma. MRI of the left axillary region (A) showing a tumor (arrow) involving neural vessels and bundles. Ultrasound (B) showing an infiltrative muscle lesion (arrow), with peripheral calcification in the pectoral/left axillary region and no detectable vascularization on the Doppler flow study. Positron emission tomography (C) and CT (D) showing an infiltrative lesion (arrow) in the left retrosternal/axillary region, with a marked increase in glycolytic activity. The imaging aspect, together with the clinical history, was definitive of myositis ossificans.