Bile ductal mucosal dysplasia as a risk factor of adenocarcinoma in patients with adenomyomatous hyperplasia of the Vaterian System

Objective: The aim of this study was to retrospective analysis of role of ductal glandular dysplasia as a risk factor in the development of carcinoma in adenomyomatous hyperplasia of the Vaterian system(AV). Methods: Retrospective collection of data from patients who underwent surgery between January 2005 and December 2021, with a final pathological diagnosis of adenomyomatous hyperplasia (AH). Clinical data and pathological features of AV with or without glandular dysplasia were analyzed. Results: Three of seventeen AH cases were associated with carcinoma (18%). Of three cases, two (12%) with the tumor lesions in the mucosal glands adjacent to the AH (cholangiocarcinoma and ampullary carcinoma), and one (6%) with carcinoma developed from AH itself in the ampulla of Vater. All carcinomas had adenomyomatous hyperplasia with nearby mucosal glandular dysplasia (MGD). The incidence of BTC or AC was higher in patients with concurrent AH and MGD compared to AH patients without MGD. The results show tendency toward statistical significance (P = 0.082). This difference was more obvious among AH with severe dysplasia compared to adenomyomatous hyperplasia with mild-moderate dysplasia (P = 0.018). Conclusion: This study is the first to find that adenomyomatous hyperplasia of the Vaterian system is associated with ductal carcinoma and ampullary carcinoma. In AV, the mucosal glandular dysplasia is a risk factor for the development of malignancy. The underlying mechanism for carcinogenesis of the Vaterian system could be AH itself or its secretions stimulating mucosal glands hyperplasia, then mucosal glands dysplasia. AH of the Vaterian system may be a precancerous lesion.