Bone involvement in hairy cell leukemia.

Four patients with a diagnosis of hairy cell leukemia complicated by bone involvement are described. This is an uncommon complication of the disease. Manifestations included osteolytic lesions, severe osteoporosis, and aseptic necrosis of the femoral head. The osseous complications do not seem to bear on the prognoses for these patients. Radiotherapy or chemotherapy provides symptomatic relief and may prevent further morbidity from the bone lesions.