title: Mantle cell lymphoma with plasma cell differentiation.
abstract: The differentiation of B lymphocytes into plasma cells (PCs) is an antigen-mediated process that largely depends on the interaction between B cells and regulatory factors in their microenvironment. Long-lived PCs are derived from activated B cells in the germinal center (GC), whereas PC differentiation from naive B cells occurs in the extrafollicular areas and the PCs are short-lived. Consequently, lymphomas arising from post-GC B cells often exhibit plasmacytic differentiation, whereas lymphomas arising from naive B cells less commonly show plasmacytic differentiation. Herein, we report 2 cases of mantle cell lymphoma (MCL) with clonal PC differentiation. Both cases presented with the typical cytologic features of MCL and were characterized by a nodular and mantle-zone growth pattern. Clusters of clonal PCs with monotypic kappa light chain expression were identified in the centers of the tumor nodules and within reactive GCs. FICTION (Fluorescence immunophenotyping and Interphase Cytogenetics as a Tool for the Investigation Of Neoplasms) analysis demonstrated the characteristic t(11;14)(q13;q32) in both the MCL cells and clonal PCs, indicating that both cell types were derived from the same B-cell clone. These findings indicate that the clonal PC differentiation may occur within GCs in some cases of MCL.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Wisconsin Hospital and Clinics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
authors.forename: Ken H
authors.initials: KH
authors.lastname: Young
authors.forename: Wing C
authors.initials: WC
authors.lastname: Chan
authors.forename: Kai
authors.initials: K
authors.lastname: Fu
authors.forename: Javeed
authors.initials: J
authors.lastname: Iqbal
authors.forename: Warren G
authors.initials: WG
authors.lastname: Sanger
authors.forename: Anne
authors.initials: A
authors.lastname: Ratashak
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Greiner
authors.forename: Dennis D
authors.initials: DD
authors.lastname: Weisenburger
mesh_terms: D003937:Diagnosis, Differential; D018858:Germinal Center / Q000473:pathology; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000096:biosynthesis; D007150:Immunohistochemistry; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D016393:Lymphoma, B-Cell / Q000473:pathology; D020522:Lymphoma, Mantle-Cell / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000473:pathology*; D033581:Stem Cell Transplantation
chemical_list: D007145:Immunoglobulin kappa-Chains