Bizarre Parosteal Osteochondromatous Proliferation (Nora's Lesion)

This photomicrographs shows cartilage maturing into bone. Spindle cells can be seen in the background. The cartilage in BPOP is usually hypercellular and there may be enlarged, hyperchromatic, or binucleated chondrocytes potentially creating confusion with chondrosarcoma (if clinical and/or radiographic information is not available)