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Mature B-Cell Leukemias With More Than 55% Prolymphocytes
A Heterogeneous Group That Includes an Unusual Variant of Mantle Cell Lymphoma

Ellen Schlette MD, Carlos Bueso-Ramos MD, Francis Giles MD, Armand Glassman MD, Kimberly Hayes, L. Jeffrey Medeiros MD
DOI: http://dx.doi.org/10.1309/PPK0-TJUK-1UAR-3194 571-581 First published online: 1 April 2001


We studied 20 cases of mature B-cell leukemia with more than 55% prolymphocytes in peripheral blood or bone marrow, fulfilling the French-American-British criteria for B-cell prolymphocytic leukemia (PLL). Cases segregated into 3 groups: de novo PLL, 6; PLL occurring in patients with a previous well-established diagnosis of chronic lymphocytic leukemia (PLL-HxCLL), 10; and t(11;14)(q13;q32)-positive neoplasms, 4. All cases expressed monotypic immunoglobulin light chain, and most were positive for CD5. All t(11;14)-positive neoplasms were CD23– and uniquely positive for cyclin D1. Cytogenetic abnormalities were present in 19; in all 19, the karyotype was complex, indicating clonal evolution and genomic instability. The most frequent cytogenetic abnormality in de novo PLL involved chromosome 7 in 4 cases. Trisomy 12 or add(12p) was present in 4 cases of PLL-HxCLL. We conclude that mature B-cell leukemias with more than 55% prolymphocytes are a heterogeneous group that includes t(11;14)-positive neoplasms, which we suggest are best classified as mantle cell lymphoma. We also suggest that prolymphocytic morphologic features are a common end-stage of transformation for several B-cell neoplasms.

Key Words:
  • Prolymphocytic leukemia
  • Chronic lymphocytic leukemia
  • Mantle cell lymphoma
  • Immunophenotype
  • Cyclin D1
  • t(11;14)