An unusual case of co-existing classic mantle cell lymphoma and transformed lymphoma with Burkitt-like features with leukemic presentation

Mantle cell lymphoma (MCL) is an aggressive mature B cell lymphoma characterized by the t(11;14) IGH-CCND1 translocation. The majority of the MCL harbors secondary genetic aberrations and the MYC gene rearrangement is occasionally detected. We reported a unique case of co-existence of a typical MCL and a transformed component with morphologic and immunophenotypic features resembling a Burkitt lymphoma in leukemic phase at disease presentation. Two distinct abnormal B cell populations were identified in the peripheral blood and bone marrow: a CD5+/CD10− population primarily in the peripheral blood (47.6 %) and a CD5−/CD10+ population predominantly in the marrow (83.8 %), which shared the same surface light chain restriction and identical immunoglobulin gene rearrangements. By cytogenetic studies, the CD10+ cells harbored both t(11;14) IGH-CCND1 and t(8;14) IGH-MYC whereas the CD5+ population only carried t(11;14) IGH-CCND1. The combined findings indicate that the Burkitt-like component represents a transformation from a typical MCL by acquiring t(8;14) and that the MYC rearrangement represents a secondary oncogenic event in MCL that drives the disease progression. This unique case described co-existence of clonally related MCL and a transformed component otherwise typical of a Burkitt lymphoma, both in leukemic phase at disease presentation, which provided direct evidence on the lymphomagenesis of MCL.