Bizarre parosteal osteochondromatous proliferation of the clavicle

Abstract

Bizarre parosteal osteochondromatous proliferation (BPOP) is a rare osteocartilaginous lesion of bone composed of a disorganized mixture of cartilage, bone, and fibrous tissue.1,8,11 It arises most commonly in the small bones of the hands and feet but also has been reported in other bones, including the long bones of the upper and lower limb.1,3,5,17 BPOP is thought to be a reactive lesion, closely related to florid, reactive periostitis, subungual exostosis, and turret exostosis.6,19,20 BPOP presents as an exophytic osteocartilaginous outgrowth that arises on the bone surface.