Gastrointestinal Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma with Synchronous Precancerous/Malignant Epithelial Mucosal Lesions: A Clinico-Pathologic Review

Abstract

Introduction/Objective Mucosa-associated lymphoid tissue (MALT) lymphoma of the gastrointestinal(GI) tract and synchronous precancerous/malignant epithelial lesions have been sporadically reported in literature. We sought to assess the incidence of GI MALT lymphoma and synchronous epithelial lesions. Methods/Case Report We performed a retrospective study by searching the pathology files at our institution from 1992 to December 2021, for GI lymphomas including extranodal marginal zone lymphoma(E-MZL). Results (if a Case Study enter NA) There were a total of 178 cases of lymphoma involving the GI tract. The basis of this report was formed by the 40/178(22.5%) cases, which were E-MZL. Twenty-four were males and 16 females(age range:37-80 years; mean:62 years). Sites of tumors were stomach(21), colon(6), ileum(4), duodenum(4), rectum(3), and cecum(2). Four cases were multifocal. Lymph nodes were assessed in 8/40, of which 4 were positive. One patient had malignant pleural effusion and another had retroperitoneal soft-tissue involvement. Overall, 11/40(27.5%) cases had a synchronous precancerous/malignant epithelial lesion. Gastric E-MZL were the most common (21), out of which 8(38%) were associated with synchronous epithelial lesion (3 gastric adenocarcinomas and 5 tubular adenomas(TA) at different colorectal locations). Out of 6 colonic E-MZL, 2 were associated with synchronous TAs at different colorectal sites and one rectal E-MZL was associated with cecal TA. Conclusion In our cohort, precancerous/malignant epithelial lesions were seen in 11/40(26.8%) of GI E-MZL cases. Gastric adenocarcinomas comprised 3/8 (37.5%) of gastric synchronous precancerous/malignant epithelial lesions; the association of E-MZL and gastric adenocarcinoma is well-known, arising in the background of chronic atrophic gastritis and intestinal metaplasia secondary to chronic inflammatory disorders. The remaining 8 cases of synchronous mucosal epithelial lesions were TAs at different colorectal sites. Based on our observations, unlike gastric adenocarcinoma, the association of colorectal pre-cancerous lesions with E-MZL is less likely, since, in all cases, the TAs were seen in sites other than E-ZML sites and also, sporadic colorectal TAs are a common pathology. However, possible association between E-MZL and precancerous mucosal epithelial lesions needs more work and further investigation.