352 Histological Diagnoses After Cholecystectomy for Benign Disease: Interim Results from the Feasibility of Predicting Incidental Gallbladder Cancer (fP-iGBC) Study

Abstract Aim Cholecystectomy is commonly performed for symptomatic gallstone disease, gallbladder polyps, and occasionally gallbladder dyskinesia. Gallbladder specimens are routinely examined histologically to exclude dysplasia and malignancy, although selective analysis has been proposed. The aim of this secondary interim analysis of Feasibility of Predicting Incidental gallbladder Cancer (fP-iGBC) was to describe final histopathological findings in adults undergoing cholecystectomy for benign disease. Method fP-iGBC prospectively identified 508 consecutive adult patients undergoing cholecystectomy for benign disease across eight units in South West England between October 2024 and March 2025. Patients at high risk of gallbladder malignancy, including those with high-risk polyps, were excluded. For this interim analysis, histological findings were summarised using descriptive statistics. Results Final histology was available for 504 patients (99.2%). The most common histological findings were chronic cholecystitis (436, 86.5%) and acute cholecystitis (61, 12.1%). Other benign findings included cholesterolosis (90, 17.9%), xanthogranulomatous cholecystitis (13, 2.6%) and adenomyomatosis (10, 2.0%). Low-grade dysplasia was identified in six (1.2%) specimens, of which one (16.7%) had a positive margin. High-grade dysplasia was identified in two (0.4%), both with positive margins, and invasive malignancy (adenocarcinoma, T4) in one (0.2%). The combined rate of malignancy and dysplasia was 1.8%. Conclusions This interim analysis demonstrates that histological findings requiring follow-up are uncommon. However, the observed rate of incidental dysplasia and malignancy is consistent with previously published data and supports the continued practice of routine histopathological analysis. These provisional findings reinforce the need for robust, locally validated risk stratification tools before selective analysis can be considered in the UK.