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Osteosarcoma associated with osteochondritis dissecans. A case report and review of the literature.

Sarcoma associated with a bone infarct is fairly unusual; we are aware of only forty-nine well documented cases (in forty-seven patients)1-10,12-20. Of these forty-nine tumors, thirty were malignant fibrous histiocytomas; nine, osteosarcomas; five, fibrosarcomas; three, angiosarcomas; and two, poorly differentiated sarcomas. All occurred in a non-epiphyseal region of a long bone. In the present report, we describe the case of an elderly woman in whom an osteosarcoma was found incidentally on examination of bone that had been removed to perform a total knee replacement. The osteosarcoma was located within an area of osteochondritis dissecans in the medial femoral condyle. To our knowledge, we are the first to report a sarcoma arising from an area of osteochondritis dissecans.

A sixty-seven-year-old white woman had had increasing pain in the right knee for several months. There was only minimum relief of pain after the administration of non-steroidal anti-inflammatory medications and an injection of cortisone. The patient had no history of alcoholism or alcohol consumption; cardiac, pulmonary, renal, or hepatic disease; Gaucher disease; pancreatitis; or a dysbaric condition. Physical examination revealed a painful arc of motion and an antalgic gait, but there was no ligamentous laxity, joint-line tenderness, effusion, or mass. Pertinent laboratory data, including a complete blood-cell count and blood-chemistry levels, were normal. The white blood-cell count was 8.3 × 109 per liter, the level of hemoglobin was 115 grams per liter, the erythrocyte sedimentation rate was twelve millimeters per hour, the serum calcium level was 2.22 millimoles per liter, the serum phosphate level was 1.00 millimole per liter, and the serum alkaline phosphatase level was seventy-six international units per liter. A plain radiograph of the right knee, made in March 1992, showed only mild narrowing of the joint space (Fig. 1). A T1-weighted …