Marked Thickening of Muscularis Mucosae and Submucosa in the Gastric Cardia: A Histopathologic Study of 110 Surgical Resection Cases.

OBJECTIVE: We aimed to investigate muscularis mucosae and submucosa in the gastric cardia. METHODS: We performed a histopathology study in 50 distal esophagectomies with proximal gastrectomies for esophageal squamous carcinoma as the study (non-cancerous cardiac) group and 60 gastrectomies for early gastric cardiac carcinoma as the cancer group. The gastroesophageal junction was defined as the distal end of squamous epithelium, multi-layered epithelium, or deep esophageal glands/ducts. Gastric cardia (N = 110) was defined as the presence of cardiac and cardio-oxyntic mucosae distal to the gastroesophageal junction. RESULTS: The average thickness of muscularis mucosae and submucosa in the cardia was 1.04 mm and 1.52 mm, respectively, significantly thicker than that in distal stomach (N = 34) (0.22 mm and 1.12 mm) or distal esophagus (N = 92) (0.60 mm and 1.22 mm). In the cardia, thickened muscularis mucosae displayed frayed muscle fibers (93.33%) with a significantly higher prevalence of entrapped glands, cysts, and lymphoid follicles than in distal stomach or distal esophagus. In the submucosa, the presence of fatty changes, cysts, and abnormal artery was significantly more common in the cardia than in distal stomach or distal esophagus. Compared to the study group, the cardia in the cancer group showed significantly thicker muscularis mucosae (average 1.31 mm, vs. 0.72 mm) and submucosa (average 1.61 mm, vs. 1.16 mm), more frequent presence of the frayed muscularis mucosae (93.33%, vs. 60.0%), prolapse-like changes (50.0% vs. 2.0%), and cysts (26.67%, vs. 4.0%). CONCLUSION: Muscularis mucosae and submucosa of the cardia were significantly thickened, especially in early gastric cardiac carcinomas. This article is protected by copyright. All rights reserved.