Bone infarct-associated osteosarcoma.

Reported is a patient with an osteosarcoma arising in a medullary infarct of the humerus. Infarct-associated sarcoma (IAS) of bone is rare. In a collective review of 50 cases reported in the medical literature, only 37 were fully documented. Including our patient, 26 men and 12 women, ranging in age from 18 to 82 years (mean, 53.4 years) have been reported. Black patients appeared to be disproportionately represented, accounting for 36% of the group. In most patients, there was no known cause for the infarct, whereas in the remainder, the most common underlying condition was a prior dysbaric event or alcoholism. Approximately 75% of the patients had multiple bone infarcts. The femur was involved in 21 patients, the tibia in 14, the humerus in 2, and the radius in 1. Among 40 sarcomas in these patients, 7 (18.4%) were osteosarcomas, and 29 (72.5%) were malignant fibrous histiocytomas. The survival rate in patients with IAS is poor: 5 of the 7 patients with osteosarcoma (71%) and 20 of the 31 other patients (65%) died of tumor. Eight patients are alive and well, all for longer than 5 years.