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.

Clinicopathological characteristics of primary gastric T‐cell lymphoma

“…CD8+ GTCL was found in only two cases (10%) in the present study, among which enteropathy‐like invasion was seen in one case. Of the previously reported GTCL, five (18%) cases showed CD8+ and TIA1+ and CD56− lymphoma, and the two cases showed frequent IELs and enteropathy‐like invasion by lymphoma cells as in intestinal ETCL 8,21,31,34 . These findings support the notion that CD8+ GTCL occasionally occurs in the stomach and may be derived from CD8+ IELs.…”

“…Thirty‐four cases of primary GTCL were selected from 15 reports in the English literature from 1988 to 2007 8,9,21–34 . Histological evaluation was performed from the reported findings of surgical specimens in 27 of these cases and biopsy specimens in the remaining seven cases.…”

Endocytoscopic findings of lymphomas of the stomach

“…When T-cell lymphomas develop in the stomach, they usually occur in association with infection by human T-lymphotropic virus type 1 (HTLV-1), especially in endemic areas such as Japan [6-8]. Adult T-cell leukemia/lymphoma (ATLL) is a devastating T-cell malignancy caused by HTLV-1 [7,8].…”

“…Sakata et al demonstrated gastric infiltration of ATLL cells in 23 of 76 patients with ATLL (30.3%) [9]. In contrast, the other gastric T-cell lymphomas without HTLV-1 infection are reported sporadically [6]. …”

Gastric lymphoma

“…Primary gastric T-cell lymphoma without HTLV-1 infection is rare, and sporadic cases have been reported. 9 The age of most gastric lymphoma patients is over 50 years with a relative predilection in males.…”