Popliteal pseudoaneurysm caused by an adjacent osteochondroma: a case report and review of the literature.

A male 17-year-old with multiple hereditary exostoses presented with a mass in the distal left thigh several days after lifting weights. An arteriogram showed a popliteal artery pseudoaneurysm adjacent to a femoral osteochondroma. The osteochondroma was excised and the artery was repaired with a saphenous vein interposition graft. A review of the literature identified 23 similar reports. The average age of the patients was 21.3 years. Seventy-eight percent were men and half of the patients had multiple hereditary exostoses. Ten patients were initially misdiagnosed. The clinician should consider the diagnosis of pseudoaneurysm in a young patient with an osteochondroma and a mass about the knee.