Periosteal chondroma of the rib--report of a case and literature review.

Periosteal chondroma is a rare benign tumor of hyaline cartilage. It develops adjacent to the cortex of the bone and is rimmed by an intact periosteal membrane. Periosteal chondromas are most common in the metaphyses of long bones followed by the small tubular bones of the hands and feet. Periosteal chondroma arising in the rib is an extremely rare event. We could only find 10 reported cases in the English literature. We present a case of periosteal chondroma in the rib discovered incidentally on chest x-ray of an 11-year-old girl.