Fig. 3

BPOP arising from the distal ulnar metaphysis. On X-rays, frontal (a) and lateral (b) views show a well-defined mass of heterotopic mineralization, which is contiguous to the palmar aspect of the distal ulnar metaphysis. On axial (c) and sagittal (d) CT images, the mass is cortex-based with no cortico-medullary continuity, cortical breakthrough, or marrow extension. On axial T1-weighted (e) and T2-weighted (f) MRI sequences, the mass shows low-to-intermediate and high signal, respectively. After contrast administration, marked contrast enhancement is seen on sagittal fat-saturated T1-weighted sequence (g). After biopsy, surgical resection was performed and BPOP was pathologically proven. Arrow points at BPOP in all images