[Malignant hemangiopericytoma--a soft tissue and bone tumor]

Hemangiopericytomas are very rare tumors that mostly develop in the soft tissues. In rare cases, however, they may occur as primary bone tumors which are extremely rare. In case of such an intraosseous tumor, a bone metastasis of such a soft tissue sarcoma must be considered first and has to be excluded. In a 62 year old female, a hemangiopericytoma of the left femoral neck was diagnosed that had induced a pathological bone fracture. A resection of the femoral head and neck was performed. Anamnestical investigations, however, have shown that 4 years before, such a tumor of the pelvic soft tissues was removed. Thus, the lesion of the femoral neck had to be classified as bone metastasis of a malignant hemangiopericytoma. It has to be emphasized that this special tumor always shows a questionable prognosis and, by histological investigations, it cannot be decided if we are dealing with a benign or malignant tumor growth. Diagnostic managements and clinical problems with hemangiopericytomas are discussed in detail.