title: Most CD56+ intestinal lymphomas are CD8+CD5-T-cell lymphomas of monomorphic small to medium size histology.
abstract: The expression of the natural killer (NK) cell marker CD56 has been reported to occur in NK cell lymphomas/leukemias and a small group of peripheral T-cell lymphomas but has not been studied extensively in primary intestinal non-B-cell lymphomas. Normal human jejunal intraepithelial lymphocytes (IELs) are mainly T-cell receptor (TCR)-alphabeta+CD3+CD8+CD5low and include an approximately 15% fraction of CD56+ cells that could be the cells of origin for CD56+ intestinal T-cell lymphoma (ITL). To test this hypothesis, 70 cases diagnosed as ITL were immunophenotyped, and 15 CD56+ cases (21%) were identified. The majority of the CD56+ lymphomas was of monomorphic small to medium-sized histology, shared the common phenotype betaF1+/-CD3epsilon/cyt+CD8+CD4-CD5-CD57-TIA-1+ and had clonally rearranged TCR gamma-chain genes. In contrast, the CD56- lymphomas were mainly composed of pleomorphic medium and large cells or had a morphology most consistent with anaplastic large-cell lymphoma and were mostly CD8-. These findings suggest that the majority of CD56+ intestinal lymphomas are morphologically and phenotypically distinct T-cell lymphomas most likely derived from activated cytotoxic CD56+CD8+ IELs. Some overlapping histological and clinical features between CD56+ and CD56- ITLs indicate that the former belong to the clinicopathological entity of ITL. The consistent expression of cytotoxic-granule-associated proteins introduces ITL (both CD56+ and CD56-) into the growing family of usually aggressive extranodal lymphomas of cytotoxic T-cell and NK-cell derivation. In contrast to putative NK-cell lymphoma of the sinonasal region, intestinal NK-cell lymphoma seems to be very rare.
authors.affiliation: Department of Clinical Pathology, University of Vienna, Austria. chott@akh-wien.ac.at
authors.forename: A
authors.initials: A
authors.lastname: Chott
authors.forename: W
authors.initials: W
authors.lastname: Haedicke
authors.forename: I
authors.initials: I
authors.lastname: Mosberger
authors.forename: M
authors.initials: M
authors.lastname: Födinger
authors.forename: K
authors.initials: K
authors.lastname: Winkler
authors.forename: C
authors.initials: C
authors.lastname: Mannhalter
authors.forename: H K
authors.initials: HK
authors.lastname: Müller-Hermelink
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D018956:CD5 Antigens / Q000032:analysis*; D019002:CD56 Antigen / Q000032:analysis*; D016827:CD8 Antigens / Q000032:analysis*; D002999:Clone Cells / Q000737:chemistry; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007414:Intestinal Neoplasms / Q000737:chemistry / Q000276:immunology* / Q000473:pathology; D016399:Lymphoma, T-Cell / Q000737:chemistry / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology
chemical_list: D014408:Biomarkers, Tumor; D018956:CD5 Antigens; D019002:CD56 Antigen; D016827:CD8 Antigens; D016692:Receptors, Antigen, T-Cell, gamma-delta