[Diagnosis and differential diagnosis of hairy cell leukemia].

On account of 2 own observations, main clinical and diagnostic features of Hairy cell leukemia (HCL) will be discussed. HCL is a rare, unusual type of chronic leukemia and is predominantly particular of middle-aged men. The occurrence of middle-sized lymphoid cells having a hairy cytoplasmic edge, and a tartrate-resistant acid PHOsphatase isoenzyme are the characteristic criteria of the HCL. The diffuse infiltration by hairy cells affecting primarily the spleen and bone marrow results in anaemia, granulocytopenia, thrombocytopenia and splenomegaly. Differential diagnosis have to be made in relation to other lymphatic leukemias, leukemic malignant lymphomas and monoclonal gammopathies as well as lymphotropic viral infections. Immunologic behaviour of hairy cells is like that of B-lymphocytes. Therefore, the term "leukemic reticuloendotheliosis" should no longer be applied.