FIG. 3. Imaging results for a 16-year-old boy with bizarre parosteal osteochondromatous proliferation. (A) Anteroposterior radiograph showing a cortical-based bony excrescence (arrow) of the distal ulna diaphysis. (B) Τ1- and Τ2-weighted magnetic resonance images (sagittal, axial) showing an abnormal mass (arrow) extending around the medial aspect of the distal ulna. Bone marrow, medullary cavity and adjacent soft tissues appear normal. (C) Anteroposterior and lateral radiographs obtained 16 months after second excision.