Bizarre parosteal osteochondromatous proliferation of bone (BPOP): an unusual foot mass in a child.

This report describes an unusual case of bizarre parosteal osteochondromatous proliferation of bone (BPOP) which developed in the foot of an eight year-old child. Also described as Nora's lesion, BPOP is a rare benign bone tumor found most commonly in the hands and feet with a radiographic appearance occasionally confused with malignancy. Resembling osteochondromas at first glance, these lesions have a distinct radiographic and histologic appearance that permits differentiation from other benign lesions or low-grade malignant tumors. Treatment of BPOP consists of simple excision, although there is high rate of recurrence. Despite this high recurrence rate, there have been no reported metastases and local excision is still recommended.