Leukemic meningitis in a patient with B-cell prolymphocytic leukemia.

(48.55 g/L) was detected. She received treatment with three courses of chlorambucil and prednisone and responded well. On current admission blood cell counts were as follows: hematocrit 22%, leukocytes 71.37310/L (5% neutrophils, 92% lymphocytes with lymphoplasmacytic appearance), platelets 66310/L. IgM paraprotein level was 60 g/L. Immunophenotype of the leukemic population gave the following results: CD5, CD19, CD23, CD22 ,CD25, cytoplasmic CD79a and FMC7 positive; CD10, CD103, CD38, BB-4 and CD11c negative. SmIg expression in the membrane was strong (Figure 1). A diagnostic problem that often arises is the differentiation of CLL with lymphoplasmacytoid features from lymphoplasmacytic lymphoma (LL) and splenic lymphoma with villous lymphocyes (SLVL). In all three diseases a paraprotein IgM can be found. LL should always be considered in cases of CD5/CD19/CD23 chronic lymphoproliferative disorders. Although rare, leukemic presentation can be misleading, especially if morphologic and clinical features are not so straightforward as in the case under discussion. Recently, immunophenotypic score systems have been proposed to differentiate between CLL and other chronic lymphoproliferative disorders. This distinction is clinically important since therapeutic implications are derived from a correct diagnosis.