An unexpected cause of pathologic hip fracture. Malignant fibrous histiocytoma.

We describe a case of a 68-year-old patient presenting with pathological hip fracture and multiple pulmonary metastases, who has been operated without a prior histological diagnosis. The hip lesion was thought to be a metastasis of an unknown primary tumor. The proximal part of the femur was resected and replaced by a Müller mega-prosthesis. Histological analysis of the resected bone revealed a malignant fibrous histiocytoma, a rare but very aggressive bone tumor. The patient died three weeks after operation of widespread metastases. By presenting this case report, we want to stress the importance of pretreatment histological diagnosis of osteolytic bone lesions in older patients with metastases.