[Chronic lymphoproliferative disorder resembling hairy-cell leukemia (author's transl)].

Seven patients are presented with a chronic lymphoproliferative disorder characterized clinically by splenomegaly, no or discrete lymphnode enlargement, and a varying degree of cytopenia. In blood and bone-marrow smears lymphoid cells of “hairy” appearance are demonstrable which may contain tartrate-resistant acid phosphatase. The finding of a nodular bone-marrow infiltration without fibrosis as well as that of a nodular infiltration of the spleen originating in the white pulp are incompatible with the diagnosis hairy-cell leukemia and place the disease near to chronic lymphocytic leukemia (CLL) or leukemic immunocytoma respectively. A detailed cytologic and cytochemical examination of the infiltrating cells shows deviations from the typical enzymatic pattern of hairy cells and from known enzymatic constellations in CLL and related lymphoproliferative disorders. Thus, we are dealing with an intermediate form, difficult to classify, the separation of which nevertheless seems to be important for therapeutical reasons.