title: BCL6 gene rearrangement and protein expression are associated with large cell presentation of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue.
abstract: Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is an indolent B-cell lymphoma, which is often localized in the stomach. It is characterized by typical morphology, immunology, cytogenetics and expression profile. The coexistence of a large B-cell lymphoma and a MALT lymphoma in the gastrointestinal tract is defined as a composite lymphoma (ComL) and, as we have previously shown, is almost always the consequence of secondary transformation of MALT lymphoma. Here, we have analyzed a panel of seven MALT lymphomas, seven ComL and thirteen large cell variants of marginal zone B-cell lymphomas (MZBL) using FISH for the detection of rearrangements of IGH, MALT1, BCL6, BCL10 and FOXP1 and immunohistochemistry for Bcl6, Bcl10 and FoxP1. Translocations involving IGH were found in 10/27 lymphomas including two cases with IGH-BCL6 fusion and one with IGH-BCL10 fusion; in 7/10 cases, the translocation partner was not identified. Bcl10 and FoxP1 protein expression was heterogeneous throughout the series. Genetic rearrangements of BCL6 and Bcl6 protein expression were found almost exclusively in the large cell components of the ComL and the large cell extranodal MZBL (p = 0.2093 and p = 0.0261, respectively). These findings suggest Bcl6 as a marker for transformation of MALT lymphoma.
authors.affiliation: Institute of Pathology, Ulm University, Ulm, Germany.
authors.forename: Lucia
authors.initials: L
authors.lastname: Flossbach
authors.forename: Elias
authors.initials: E
authors.lastname: Antoneag
authors.forename: Michaela
authors.initials: M
authors.lastname: Buck
authors.forename: Reiner
authors.initials: R
authors.lastname: Siebert
authors.forename: Torsten
authors.initials: T
authors.lastname: Mattfeldt
authors.forename: Peter
authors.initials: P
authors.lastname: Möller
authors.forename: Thomas F E
authors.initials: TF
authors.lastname: Barth
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D002869:Chromosome Aberrations; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D018442:Lymphoma, B-Cell, Marginal Zone / Q000235:genetics* / Q000473:pathology; D051560:Proto-Oncogene Proteins c-bcl-6
chemical_list: C084103:BCL6 protein, human; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D051560:Proto-Oncogene Proteins c-bcl-6