Mature B-cell acute leukemia: a clinical, morphological, immunological, and cytogenetic study of nine cases.

Nine patients who presented with acute lymphoid leukemia of mature B-cell phenotype without FAB-L3 morphology are discussed. All patients were male with a median age of 69 years. All patients had extensive bone marrow involvement at presentation with lymphoid leukemic cells in the peripheral blood. Six patients had extramedullary disease and 3 developed meningeal involvement sometime during the course of their illness. The leukemic cells were negative for terminal deoxynucleotidyl transferase in all 9 cases, and monoclonal surface immunoglobulin was demonstrated in all 8 cases evaluated with a lambda light chain predominance. Clonal chromosomal abnormalities were detected in 4 of 6 cases studied with no specific pattern identified, although abnormalities involving chromosome 8 were present in all 4 cases. Despite aggressive chemotherapy, only 2 patients achieved complete remission which was of short duration (1 month) in 1 patient. Eight patients died of their disease 1 week to 20 months after diagnosis with a median survival of 5.5 months. Mature B-cell acute leukemias that are not of the FAB-L3 type have a very aggressive clinical course and poor prognosis.