176 Histological Correlation of Prophylactically Resected Gallbladder Polyps Diagnosed at Ultrasound: A 10 Year Retrospective Study

Abstract Aim Gallbladder polyps are commonly detected incidentally on ultrasound and may represent true mucosal lesions or benign pseudopolyps (e.g. cholesterol deposits or stones). Guidelines recommend cholecystectomy for lesions >10 mm or for smaller lesions with high-risk features. However, our experience suggests that many suspected lesions are not true mucosal polyps. We aimed to determine the proportion of cholecystectomies performed for high-risk polyps which harboured true mucosal polyps. Method Histopathology databases were reviewed for gallbladder specimens submitted between January 2014 and December 2024 and reports including the term “polyp.” Records were cross-referenced with preoperative imaging and operative indication. Details of imaging findings and final histopathological diagnoses were recorded. Results 119 patients were identified who underwent prophylactic cholecystectomy for polyps which were diagnosed at ultrasound, with a median age of 58 (23-89) and median largest polyp size of 7.85mm (1-28mm). Of these, only 71 (59.7%) harboured true mucosal polyps, with a median largest polyp size of 5mm (1-25mm). TOST analysis demonstrated no size equivalence between USS and histology. In the remaining 48 gallbladders, the most common findings were cholecystitis (39.6%), Gallstones (27.1%), Cholesterolosis (27.1%) and Adenomyomatosis (8.3%). Conclusions A substantial proportion of gallbladders removed for suspected polyps did not contain true mucosal polyps. This highlights the limited specificity of ultrasound in this context and suggests that current guidelines may lead to unnecessary prophylactic cholecystectomy in at least 40% of cases. Future guidelines may wish to consider additional risk stratification to avoid over treatment.