Biclonal Diffuse Large B-cell Lymphoma Commonly Characterized by Partial Trisomy 18q Involving MALT1 and BCL2

• Published in: Internal Medicine Vol. 62; no. 2; pp. 285 - 292
• Main Authors: Yamamoto, Katsuya, Kawamoto, Shinichiro, Chijiki, Ruri, Watanabe, Marika, Matsumoto, Sakuya, Kitao, Akihito, Mizutani, Yu, Kajimoto, Kazuyoshi, Hayashi, Yoshitake, Yakushijin, Kimikazu, Minami, Hironobu
• Format: Journal Article
• Language: English
• Published: Japan The Japanese Society of Internal Medicine 15-01-2023; Japan Science and Technology Agency
• Subjects: B-cell lymphoma; Bcl-6 protein; BCL2; biclonal B-cell lymphoma; Case Report; CD20 antigen; Chromosome banding; diffuse large B-cell lymphoma; Fluorescence in situ hybridization; Heavy chains; Humans; Immunoglobulins; In Situ Hybridization, Fluorescence; Internal medicine; Karyotypes; Lymphocytes B; Lymphoma, Large B-Cell, Diffuse - genetics; Lymphoma, Large B-Cell, Diffuse - pathology; Male; MALT1; Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein - genetics; Myc protein; Phenotypes; Proto-Oncogene Proteins c-bcl-2 - genetics; Translocation, Genetic; Trisomy; Trisomy - genetics; trisomy 18; BCL2; diffuse large B-cell lymphoma; biclonal B-cell lymphoma; MALT1; trisomy 18
• ISSN: 0918-2918; 1349-7235
• DOI: 10.2169/internalmedicine.9711-22

A 68-year-old man was admitted because of a left shoulder mass and swollen right testis. Pathological examinations indicated a diagnosis of diffuse large B-cell lymphoma (DLBCL) with the CD20+BCL6+MUM1+BCL2+CD10-MYC- phenotype in both lesions. G-banding of soft tissue showed 47,XY,+18, whereas testicular cells showed 47,X,+X,-Y,der (4) t (4;18) (p15;?),del (5) (q?),+13. Fluorescence in situ hybridization detected additional MALT1 and BCL2 signals in both lesions. Southern blot demonstrated different IGH rearrangements between the soft tissue and testis. The patient was diagnosed with biclonal DLBCL with different karyotypes but similar immunophenotypes. Partial trisomy 18q involving MALT1 and BCL2 may be commonly involved in the pathogenesis of this biclonal DLBCL.