Total body irradiation-induced osteochondromata

Nine patients developed osteochondromata, a mean of 6 years after total bod y irradiation (TBI) given before bone marrow transplantation for childhood leukaemia. This represents 23% of patients receiving TBI during the period from 1981 to 1989 surviving greater than or equal to 5 years after bone mar row transplantation. The patients were followed up for a mean of 12.5 years from diagnosis of leukaemia and a mean of 2.5 years from diagnosis of oste ochondromata. No osteochondroma, including three lesions removed surgically , showed evidence of malignant change. Six patients received growth hormone for irradiation-induced growth hormone deficiency, but this did not appear to influence the natural history of the osteochondromata. Radiation-induce d osteochondromata (RIO) are often multiple and ore indistinguishable from the: more common idiopathic type. The incidence of RIO after TBI was higher than that reported after local irradiation.