Parrott AM, et al. Hematol Oncol 2020.
Mantle cell lymphomas (MCLs) are the prototypic B-cell non-Hodgkin lymphomas defined by CCND1 (or other cyclin D family gene) rearrangements. However, extremely rare cases of diffuse large B-cell lymphomas (DLBCLs) harboring CCND1 rearrangements, resulting in cyclin D1 protein expression, have also been reported. In this report, we describe an unusual primary large B-cell lymphoma of non-germinal center immunophenotype of the central nervous system (CNS) in an elderly male patient, which was
negative for CD5 and SOX11, and exhibited cyclin D1 expression. FISH analysis detected CCND1-IGH and BCL6 rearrangements. This case may represent the first report of a primary CNS DLBCL with CCND1-IGH rearrangement. The clinico-pathologic features that can help differentiate primary CNS MCL from primary DLBCL of the CNS with CCND1-IGH rearrangement are discussed.