Florid reactive periostitis ossificans of the humerus: Case report and differential diagnosis of periosteal lesions of long bones

Figure 1 Conventional radiograph at two months from onset revealing an irregular mass posterior to the distal humerus superior to the olecranon fossa.

Figure 2 Sagittal (A) and axial (B) views demonstrating fine calcifications within the mass; no boney destruction was seen.

Figure 3 Computed tomography scan 11 wk after the initial imaging showing a 2. 0 cm × 1.9 cm osseous excrescence arising from the posterior distal humeral metaphysis.

Figure 4 Histologically the lesion was composed of woven bone in the background of mildly cellular bland spindle cells [haematoxylin and eosin, original magnification x 40 × (A), and × 100 (B)].