Blastoid variant mantle cell lymphoma with aberrant expression of CD10

A 81-year-old man was referred to our department for circulating blast on a systematic blood count without tumor syndrome. Complete blood count showed: white blood cells (WBC) 4.9 x 109/L, hemoglobin 108 g/L and platelet count 171 x 109/L. The differential count in the peripheral blood was 55% neutrophils, 9% lymphocytes, 10% monocytes, 2% eosinophils and 23% of abnormal cells with blastic morphology (figure 1A-C). The bone marrow aspiration shows a normal richness without excess blasts but with 27.5% of abnormal lymphocytes which were medium to large sized, high N:C ratio, dense nuclear chromatin with irregular nuclear contours (figure 1D-F). Flow cytometry analysis performed on bone mar-row aspirate revealed a population of cells expressing CD19, CD20, CD22, CD5, CD10, FMC7 and lambda light chains. Karyotype shows loss of the Y chromosome from aging, without other abnormalities. FISH cytogene-tics studies were positive for t(11;14)(q13;32) IGH/CCND1 guiding to a diagnosis of mantle cell lymphoma (MCL). Reverse-transcription polymerase chain reaction (RT-PCR) shows a hyperexpression of BCL1. The diagnosis was made without lymph node or bone marrow biopsy. MCL is an entity characterized by the presence of t(11;14)(q13;q32) which is responsible for hyperexpression of cyclin D1 and proliferation of mature B-cells associated with CD5+ CD23-phenotype. In this case, cytological examination leads to the diagnosis of a blastic variant of MCL confirmed by cytogenetic study showing a cryptic t(11;14)(q13;q32). These variant have been described as having high proliferation rate and more aggressive clinical course [1]. Moreover, the CD10 expression found here is unusual for an MCL. Studies have shown these CD10-positive MCL are most fre-quently associated with blastic morphology and with a poorer prognosis [2]. This case illustrates the importance of accurate cytological examina-tion and additional tests at diagnosis of MCL to establish a prognosis and guide therapeutic choices.