BN SO44 - Is routine histological analysis of excised gallbladders necessary?

Abstract Background Gallbladder cancer is rare representing <1% of annual cancer diagnoses in the UK. It is more common in females (2.4/100,000 vs 1/100,000) with a peak age incidence of 85–89-years. Our trust routinely histologically analyses all resected gallbladders, over 1000 per year, regardless of indication. Our pathologists estimate that each specimen costs £75 to analyse, reflecting an annual cost of over £80,000. A 2021 systematic review suggested selective histological analysis is safe, reduces laboratory burden and costs. We aimed to assess our centre’s cholecystectomy specimens to ascertain the incidental gallbladder cancer diagnoses and explore the possibility of selective analysis. Method A retrospective search of our pathology database was carried out for the terms “cancer” and “gallbladder” from 2015 to 2018 inclusive. After exclusion of non-gallbladder primary cancers, all selected cases electronic notes were retrospectively reviewed. The primary outcome was the incidental findings of gallbladder cancer. Secondary outcomes were the indications for surgery, intraoperative findings, histological macroscopic description, final diagnosis and further management where applicable. Results We identified 4421 gallbladder specimens of which 12 (0.27%) identified cancer. The ratio of female to male diagnoses was 5:1 and the median age was 73.5 years. Of the 12 cancers, 7 (0.16%) of these were incidental findings, with 5 having surgery for symptomatic gallstones and 2 for gallbladder polyps. The 5 symptomatic gallstones patients all had grossly abnormal macroscopic appearances of the serosa, dense adhesions or exudate; all were confirmed as gallbladder adenocarcinoma. Three patients were fit enough for limited liver resection. Conclusion Our results demonstrate that across four years the rate of incidental gallbladder adenocarcinoma diagnosed by cholecystectomy was 0.16%. In all non-polypoidal cases (0.11%), the gallbladder was macroscopically abnormal. This suggests that with careful criteria, selective gallbladder histological analysis may reduce laboratory burden and therefore costs associated with elective gallbladder surgery. With increasing emphasis to improve efficiency and rationalise healthcare spending, our results suggest that selective histological analysis may be safe and effective. However, given the consequences of missing a cancer diagnosis it would require a larger scale multi centre study to support a move in this direction.