Leucémie prolymphocytaire B

Abstract

AbstractB-prolymphocytic leukemia (B-PLL) is a very rare mature B-cell leukemia occurring in elderly people. B-PLL can be diagnosed when prolymphocytes comprise more than 55% of the lymphoid cells in peripheral blood. The diagnosis can be challenging because B-PLL shares a number of biological features with other B-cell malignancies. The cytological diagnosis is difficult to establish, and may require a specialized review. It is imperative to perform immunophenotyping, because even if there is no typical profile, this analysis distinguishes B-PLL from chronic lymphocytic leukemia. Cytogenetic analysis is mandatory to guide the diagnosis and rule out a mantle cell lymphoma. There is no specific chromosomal abnormality. A complex karyotype and MYC gene abnormalities -translocation or more rarely gain and amplification, are observed in more than 70% of cases. Deletion of 17p including the TP53 gene is also common. The outcome is generally aggressive, with a poor response to chemotherapy. Three prognostic groups have recently been established according to the presence of an abnormality in the MYC gene and/or a 17p deletion. There is no consensus for treatment that relies on immunochemotherapy or targeted therapies such as inhibitors of the BCR signaling pathway or inhibitors of BCL2.