Gut-associated Lymphoid Tissue (GALT) Carcinoma in Ulcerative Colitis

Background: In ulcerative colitis (UC), the majority of colorectal carcinomas (CRC) arise in the vast colorectal mucosal domain built with mucus-producing goblet cells and columnar cells. Conversely, CRC in UC rarely evolve in the tiny, spotty gut-associated lymphoid tissue (GALT) mucosal domain. Here we review the four reported cases of colonic carcinoma developing in GALT mucosa in UC, searching for possible precursor lesions connected with the evolution of these tumours. Materials and Methods: The clinical history, age, gender, endoscopic descriptions, and the pathology (localization, gross and histological descriptions of the luminal surface) of the four UC-GALT carcinomas reported in the literature were reviewed. Results: The luminal surface in three out of the four carcinomas revealed conventional (tubular/villous) adenomas or high-grade dysplasia. All four UC-GALT-carcinomas were detected at an early stage (T1N0). Conclusion: GALT carcinomas do occur, albeit infrequently, in patients with UC. The finding that three out of the four GALT carcinomas on record were covered by conventional adenomas or by high-grade dysplasia strongly suggests that non-invasive conventional neoplasias might often precede GALT carcinomas in UC.

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