title: Angioimmunoblastic T-cell lymphoma of cytotoxic T-cell phenotype containing a large B-cell proliferation with an undersized B-cell clonal product.
abstract: Angioimmunoblastic T-cell lymphoma is a nodal peripheral T-cell lymphoma considered to be derived from CD4 follicular helper T cells. It is characterized by the proliferation of arborizing vessels, hyperplastic follicular dendritic cells, and a polymorphous lymphoid infiltrate including large B immunoblasts, which could be polyclonal, oligoclonal, or monoclonal. The polymerase chain reaction-based clonality study of lymphoproliferations is increasingly popular in the diagnostic workup. With the commercially available Biomed-2 protocols, lymphoproliferations with amplicons in the expected size ranges are considered clonal, whereas clonal products outside the expected ranges are extremely rare. We presented the case of a 60-year-old male patient with angioimmunoblastic T-cell lymphoma, in which the neoplastic T cells expressed CD8, bcl-6, and programmed death-1. Furthermore, there was a proliferation of large B cells in this tumor. The results of T-cell receptor gene rearrangement study using the Biomed-2 protocols showed clonal rearrangement with amplicons falling within the expected size ranges. Interestingly, the size of the amplicons detected by the Biomed-2 immunoglobulin heavy chain gene (IgH) rearrangement using FR2/JH primers was around 240 bp, slightly smaller than the expected size ranges. Through cloning, sequencing, and BLAST searches, we confirmed that the FR2/JH amplicon was derived from the IgH rearrangement with a deletion of a short segment. Our case illustrates that polymerase chain reaction amplicons outside the expected size ranges may still be clonal products.
authors: Department of Pathology, Chi-Mei Medical Center, Tainan, Taiwan.
authors: Yung-Liang
authors: YL
authors: Liao
authors: Sheng-Tsung
authors: ST
authors: Chang
authors: Szu-Yin
authors: SY
authors: Kuo
authors: Shu-Hui
authors: SH
authors: Lin
authors: Chi-Kuan
authors: CK
authors: Chen
authors: Kuo-Ming
authors: KM
authors: Chang
authors: Shih-Sung
authors: SS
authors: Chuang
mesh_terms: D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics / Q000378:metabolism; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D016827:CD8 Antigens / Q000096:biosynthesis; D049109:Cell Proliferation; D002999:Clone Cells; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain / Q000235:genetics; D015329:Gene Rearrangement, T-Lymphocyte / Q000235:genetics; D006801:Humans; D007119:Immunoblastic Lymphadenopathy / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D060889:Inducible T-Cell Co-Stimulator Protein; D016399:Lymphoma, T-Cell / Q000175:diagnosis / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D061026:Programmed Cell Death 1 Receptor; D051560:Proto-Oncogene Proteins c-bcl-6; D017384:Sequence Deletion; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D014057:Tomography, X-Ray Computed
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D051017:Apoptosis Regulatory Proteins; C084103:BCL6 protein, human; D016827:CD8 Antigens; D017931:DNA Primers; D004268:DNA-Binding Proteins; C556692:ICOS protein, human; D060889:Inducible T-Cell Co-Stimulator Protein; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor; D051560:Proto-Oncogene Proteins c-bcl-6