Abstract
A 68-year-old male was admitted to Okayama University Hospital because of leukocytosis and hepatosplenomegaly. During the four months prior to admission, the patient experienced malaise and easy fatigability. On examination the liver was palpable 3 cm and the spleen 5 cm below the costal margin. The peripheral leukocyte count was 57,600/mm3, 92% of which were large lymphocyte-like cells. Most of these abnormal cells exhibited many hairy cytoplasmic projections, when examined under the phase contrast microscope. These cells were negative for acid phosphatase as well as for tartrate-resistant acid phosphatase. The majority of leukemic cells had IgG immunoglobulin on the cell surface. Electron microscopy revealed the presence of a ribosome-lamellar complex in the cytoplasm. These hematological and physical findings have remained essentially unchanged for 14 months from the onset of symptoms. This case was, therefore, considered to represent a variant type of hairy cell leukemia in that hairy cells lacked acid phosphatase in the presence of all other clinical and cytological characteristics of hairy cell leukemia.
