title: Gastric T-cell lymphoma with cytotoxic phenotype.
abstract: Primary gastric lymphoma usually originates from B cells of mucosa-associated lymphoid tissue (MALT) infected with Helicobacter pylori. When T-cell lymphomas develop in the stomach, they usually occur in association with infection by human T-lymphotropic virus type 1 and gastric involvement of adult T-cell leukemia. Reported herein is a unique and informative case of gastric peripheral T-cell lymphoma with a cytotoxic phenotype that histologically mimicked, and had to be carefully distinguished from, MALT-type B-cell lymphoma. The patient, a 73-year-old woman, underwent a gastric endoscopy examination, and the histological findings suggested MALT-type gastric lymphoma. Analysis of the immunoglobulin heavy chain (IgH) gene and T cell receptor gamma (TCRgamma) gene revealed monoclonal rearrangement of the TCRgamma gene. The tumor cells exhibited mild atypia and immunoreactivity with anti-CD3, anti-CD8, anti-T-cell intracellular antigen-1, antigranzyme B and antiperforin antibodies, but not with anti-CD20, anti-CD10, and anti-CD79a antibodies. The case was finally diagnosed as gastric T-cell lymphoma with cytotoxic phenotype, and this was confirmed after surgical resection. In cases such as this, small biopsy specimens from the stomach should be examined carefully for low grade B-cell-type malignant lymphoma (MALT lymphoma), because sometimes the proliferating B cells can hide the truly malignant T cells, and rearrangement analysis is useful for diagnosing T-cell malignancy.
authors.affiliation: Department of Pathology, University Hospital of Tsukuba, Tsukuba, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Sugita
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Iijima
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Furuya
authors.forename: Junko
authors.initials: J
authors.lastname: Kano
authors.forename: Akinori
authors.initials: A
authors.lastname: Yanaka
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Ohta
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kojima
authors.forename: Masayuki
authors.initials: M
authors.lastname: Noguchi
mesh_terms: D000368:Aged; D001483:Base Sequence; D004273:DNA, Neoplasm / Q000235:genetics; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D016393:Lymphoma, B-Cell / Q000175:diagnosis / Q000473:pathology; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis / Q000473:pathology; D016399:Lymphoma, T-Cell / Q000175:diagnosis / Q000235:genetics / Q000473:pathology*; D008969:Molecular Sequence Data; D010641:Phenotype; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000473:pathology*; D013602:T-Lymphocytes, Cytotoxic / Q000473:pathology*
chemical_list: D004273:DNA, Neoplasm; D007143:Immunoglobulin Heavy Chains; D016692:Receptors, Antigen, T-Cell, gamma-delta