Osteochondroma with metaphyseal abnormalities after total body irradiation followed by stem cell transplantation.

The occurrence of osteochondroma after total body irradiation (TBI) followed by stem cell transplantation (SCT) in our institutions was described, and its clinical significance discussed. Of 305 cases treated with SCT using TBI conditioning from 1980 to 2001, 4 cases of osteochondroma were identified on clinical examination. Mean age at the time of TBI was 4.4 years (range, 1.6 to 8.0). One patient developed multiple osteochondromas. All 4 cases showed metaphyseal abnormalities, including sclerotic metaphyseal lesion, fraying, and longitudinal striation, in the area where osteochondromas occurred. Only 1 patient required resection of the tumor due to pain. Two cases had other skeletal abnormalities including slipped capital femoral epiphysis and valgus-knee deformity, which required surgical intervention to prevent or correct these deformities. Osteochondroma is one of the complications developing after TBI, possibly concurrently with the metaphyseal abnormalities as seen on radiographs. However, clinical problems arising from osteochondroma are minimal, and surgical intervention is necessary in limited cases.