舒玉炳　施鑫　冯思坛　周光新

Erdheim–Chester disease (ECD) is a rare, non-Langerhans form of histiocytosis characterized by xanthomatous tissue infiltration with foamy histocytes. The etiology is unknown. It has a wide spectrum of clinical manifestations and the  long bone is the primary site of involvement with the characteristic of bilateral, diffuse cortical sclerosis. The lesion in the femur and tibia is more common, the bone pain and arthralgias are the most frequent symptoms. Different forms of extraskeletal sites may be frequently involved. The diagnose and treatment of ECD are difficult and the prognosis is bad with a progressive deterioration and easy misdiagnose. In order to improve the understanding of the disease, a case of ECD in our hospital is reported and literatures are reviewed.