title: Waldenström macroglobulinemia caused by extranodal marginal zone B-cell lymphoma: a report of six cases.
abstract: Waldenström macroglobulinemia (WM) and its associated hyperviscosity syndrome (HVS) are generally caused by lymphoplasmacytoid lymphoma or other small B-cell lymphoproliferative disorders. WM associated with extranodal marginal zone B-cell-mucosa-associated lymphoid tissue lymphoma (EMZL/MALT-type) has not been emphasized. We describe 4 men and 2 women (age, 40-79 years) with clinical and laboratory manifestations of WM and EMZL/MALT-type involving one or more sites: lung, pericardium/pleura, ocular adnexa, nasopharynx, minor salivary gland, glossopharyngeal fold, skin, and stomach. The following immunophenotypic patterns were observed: CD20+, 6; CD43+, 3; kappa light chain restriction, 5; and lambda light chain restriction, 1. All were negative for CD5, CD10, and cyclin D1 expression. A clonal paraproteinemia was present in each (IgM kappa, 4; IgM lambda, 1; biclonal IgM kappa/IgA kappa, 1). All 4 patients tested had elevated plasma viscosity; clinical HVS occurred in 3, and 2 required emergency plasmapheresis. These findings suggest that EMZL/MALT-type can cause WM and that the laboratory evaluation of EMZL/MALT-type should include serum protein electrophoresis/immunofixation, and plasma viscosity measurements and urine immunofixation in select cases. EMZL/MALT-type should be considered in the differential diagnosis in patients with clinicopathologic features of WM.
authors.affiliation: Department of Pathology, University of Michigan Health System, Ann Arbor 48109, USA.
authors.forename: R
authors.initials: R
authors.lastname: Valdez
authors.forename: W G
authors.initials: WG
authors.lastname: Finn
authors.forename: C W
authors.initials: CW
authors.lastname: Ross
authors.forename: T P
authors.initials: TP
authors.lastname: Singleton
authors.forename: J A
authors.initials: JA
authors.lastname: Tworek
authors.forename: B
authors.initials: B
authors.lastname: Schnitzer
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D014408:Biomarkers, Tumor / Q000378:metabolism; D001809:Blood Viscosity; D002999:Clone Cells; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D008198:Lymph Nodes / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D018442:Lymphoma, B-Cell, Marginal Zone / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010265:Paraproteinemias; D008258:Waldenstrom Macroglobulinemia / Q000209:etiology* / Q000378:metabolism / Q000473:pathology
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor