title: Mucosa-associated lymphoid tissue lymphoma of the thymus: a case report with no evidence of MALT1 rearrangement.
abstract: We report a case of thymic mucosa-associated lymphoid tissue (MALT) lymphoma (TML) that presented as an asymptomatic mediastinal mass in a 40-year-old woman with a past history of Sjögren syndrome. This case had the characteristic clinical and pathological features of TML, as found in most of the 24 previously reported cases, i.e., autoimmune context, especially Sjögren syndrome, IgA secretion, large epithelial cysts, lymphoepithelial lesions involving residual Hassal's corpuscles, epithelial cysts, and a marked plasmacytic differentiation with IgA expression. Reverse-transcription polymerase chain reaction for t(11;18)(q21;q21) was negative, in agreement with recently published data. In this case, investigation for t(14;18)(q32;q21) using fluorescent in situ hybridization was also performed and supplied negative results. Neoplastic cells were negative for MAL, a marker of primary mediastinal large B cell lymphoma (PMBL). Altogether, these findings further support that among MALT lymphomas, TML have peculiar clinical and morphological characteristics and appear not to involve MALT1 rearrangement. They also suggest the absence of a relationship between TML and PMBL.
authors.affiliation: Département de Pathologie, Hôpital Henri Mondor, AP-HP, avenue du Maréchal de Lattre de Tassigny 51, 94010 , Créteil, France. nicolas.ortonne@hmn.ap-hop-paris.fr
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ortonne
authors.forename: Christiane
authors.initials: C
authors.lastname: Copie-Bergman
authors.forename: Philippe
authors.initials: P
authors.lastname: Remy
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Delfau-Larue
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Alonso
authors.forename: Xavier
authors.initials: X
authors.lastname: Mariette
authors.forename: Judith
authors.initials: J
authors.lastname: Dierlamm
authors.forename: Karen
authors.initials: K
authors.lastname: Leroy
authors.forename: Philippe
authors.initials: P
authors.lastname: Gaulard
mesh_terms: D000328:Adult; D020169:Caspases; D002869:Chromosome Aberrations; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D017404:In Situ Hybridization, Fluorescence; D018442:Lymphoma, B-Cell, Marginal Zone / Q000235:genetics* / Q000276:immunology / Q000473:pathology*; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein; D009363:Neoplasm Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012859:Sjogren's Syndrome / Q000276:immunology; D013953:Thymus Neoplasms / Q000235:genetics* / Q000276:immunology / Q000473:pathology*; D014178:Translocation, Genetic
chemical_list: D007070:Immunoglobulin A; D009363:Neoplasm Proteins; D020169:Caspases; C400109:MALT1 protein, human; D000074884:Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein