Hemangiopericytoma of bone--a case report.

A case of low grade hemangiopericytoma of three years duration occurring in the upper end of the femur of a 70 year old man is described. Radiologically, the upper third of the right femur showed a destructive expansile osteolytic lesion with soft tissue extension. The tumour was partially encapsulated. Mitoses were 0-1 per 10 high power fields, suggesting the low grade malignant nature of the lesion. It is felt that all hemangiopericytomas occurring in bone should be considered biologically malignant.