Mantle Cell Lymphoma

Abstract

Mantle cell lymphoma (MCL) is a type of mature B-cell non-Hodgkin lymphoma with characteristic morphology and immunophenotype, which typically presents in elderly patients with advanced disease and shows a poor prognosis. On the molecular level, MCL is characterized by the translocation t(11;14)(q13;q32) resulting in juxtaposition of the bcl-1 locus on 11q13 to the immunoglobulin heavy chain gene region, resulting in deregulation of CCND1/PRAD1, the gene encoding the cell cycle protein cyclin D1. The inappropriate expression of cyclin D1 protein is the diagnostic hallmark of this lymphoma and is considered the first step in its pathogenesis, although it is not sufficient for full malignant transformation and requires additional molecular alterations mostly affecting cell cycle regulation or DNA damage response to cause manifest disease. Recently, a rare, cyclin D1-negative variant of MCL with otherwise identical clinical, morphological, and phenotypic features has been identified, in the majority of the cases characterized by translocations involving CCND2/cyclin D2.