Hairy cell leukemia: diagnosis and management.

Long-term follow-up of 18 patients with hairy cell leukemia seen at a single institution is reported: diagnostic and therapeutic modalities are described. Although the clinical features of this disease are homogeneous, it is frequently misdiagnosed initially. Bone marrow biopsy was diagnostic in all 17 patients studied prior to splenectomy. The presence of circulating "hairy" cells is greatly variable. The cause of pancytopenia is unclear: splenic sequestration was not demonstrated by 51Cr red cell studies in three of four patients. In most patients, splenectomy resulted in amelioration of pancytopenia. No clinical features prior to splenectomy could predict response to surgery. The results of chemotherapy and splenic irradiation were variable and unpredictable. Although bone marrow infiltration persists following splenectomy, this remains the only established therapy in hairy cell leukemia and is usually followed by long, uncomplicated survival.