[Successful treatment by ranimustine (MCNU) of a patient with B-cell prolymphocytic leukemia (B-PLL)].

A 66-year-old female was admitted to our hospital because of leukocytosis, anemia and splenomegaly in August 1989. The white cell count was 3.49 x 10(10)/l with 88.5% of the leukemic cells which were morphologically similar to prolymphocytes. On flowcytometric analysis, the leukemic cells were found to be positive for B-cell markers such as CD19, CD20, FMC7, Sm-IgM and Sm-IgD and negative for CD5 and CD25. The chromosome analysis demonstrated hyperdiploidy of 48, XX, (+3, +18). She was diagnosed as having B-cell prolymphocytic leukemia, and treated with alpha-interferon and VP therapy with progression. Complete remission was achieved after three courses of ranimustine (MCNU) administration. She relapsed after about one year without therapy, but when MCNU was administered again, a secondary remission followed. The prolymphocytes during the relapse stage also had the phenotypes of CD11b, CD13 and CD25. This case is considered to be rare with respect to both complete remission by MCNU and the immunophenotypic change of leukemic cells during the relapse period.