title: CD20-negative low-grade B cell lymphoma showing immunophenotypic and genotypic features resembling plasma cell myeloma.
abstract: Here we demonstrate a unique case of CD20-negative low-grade B cell lymphoma showing immunophenotypic and genotypic features resembling multiple myeloma. The female patient had no abnormal masses, splenomegaly, swelled lymph nodes, or bone lesions. Although serum levels of IgG, IgA, and IgM were decreased without M protein, κ-type Bence-Jones protein was observed. In bone marrow, monotonous proliferation of small to medium-sized lymphoid cells was observed without classical myeloma cells, the same histological findings as lymphoplasmacytic lymphoma. The cells were CD38+, CD138+, CD43+, CD44+, CD3-, CD4-, CD5-, CD7-, CD8-, CD10-, CD11b-, CD19-, CD20-, CD21-, CD23-, CD24-, CD25-, CD27-, CD40-, CD45-, and CD56-. Surface or cytoplasmic IgM, κ, or λ were all negative. Chromosomal analysis demonstrated t(11;14)(q13;q32). The present case may belong to a new entity of low-grade B cell lymphoma with the same histological findings as lymphoplasmacytic lymphoma, mainly proliferated in bone marrow whose immunophenotype and genotype are similar to plasma cell myeloma.
authors.affiliation: Department of Internal Medicine, Hyogo Prefectural Tsukaguchi Hospital, Hyogo, Japan. rtabata@hp.pref.hyogo.jp
authors.forename: Rie
authors.initials: R
authors.lastname: Tabata
authors.forename: Ryoji
authors.initials: R
authors.lastname: Yasumizu
authors.forename: Chiharu
authors.initials: C
authors.lastname: Tabata
authors.forename: Masaru
authors.initials: M
authors.lastname: Kojima
mesh_terms: D000369:Aged, 80 and over; D018951:Antigens, CD20 / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D003937:Diagnosis, Differential; D005260:Female; D005434:Flow Cytometry; D020022:Genetic Predisposition to Disease; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D017403:In Situ Hybridization; D017404:In Situ Hybridization, Fluorescence; D016393:Lymphoma, B-Cell / Q000737:chemistry / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D009101:Multiple Myeloma / Q000737:chemistry / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D060787:Neoplasm Grading; D010641:Phenotype; D011237:Predictive Value of Tests
chemical_list: D018951:Antigens, CD20; D014408:Biomarkers, Tumor
keywords: Low-grade B-cell lymphoma; Lymphoplasmacytic lymphoma; Multiple myeloma; t(11 ;14)(q13 ;q32)