Sarcoma in association with bone infarcts. Report of five cases.

Sarcoma associated with bone infarct is rare, and only 41 well-documented cases have been published. We describe five additional patients, three women and two men, aged 39 to 57 years. The tumors involved the femur (three patients), tibia (one patient), and humerus (one patient). In three patients, the infarcts were idiopathic. Radiologic evidence of malignancy was found in all patients, and bone infarcts were suspected in four. Four of the patients had malignant fibrous histiocytoma and one an osteosarcoma. Histologically, bone infarcts were seen in all patients, but in three they were mostly replaced by tumor. Portions of intact infarcts were seen adjacent to the tumor, indicating that they had preceded the development of the sarcoma. No hypercellular or atypical reparative tissue was found in the infarcted bones or in three additional uncomplicated infarcts studied from the same patients. The pathogenesis of sarcoma arising in bone infarct is unknown. The prognosis is poor; four of our five patients died within 2 years.