Are Incidental Gallbladder Cancers Missed with a Selective Approach of Gallbladder Histology at Cholecystectomy?

Incidental gallbladder cancer (IGBC) is an unexpected finding when a cholecystectomy is performed upon a benign indication, and the use of routine or selective histological analysis of gallbladder specimen is still debated. The aim of this study was to investigate whether the proportion of submitted gallbladder specimens for pathological investigation influences the proportion of IGBC found, and what possible factors preoperatively or perioperatively could influence the selection process. All cholecystectomies between January 2007 and September 2014 registered in the Swedish Registry of Gallstone Surgery and ERCP (GallRiks) were included. Proportion of histological analysis was divided into four subgroups (0-25%, > 25-50%, > 50-75%, > 75-100%). A total of 81,349 cholecystectomies were registered, and 36,010 (44.3%) gallbladder specimens were sent for histological analysis. A total of 213 cases of IGBC were discovered, which constituted 0.26% of all cholecystectomies performed and 0.59% of the number of gallbladder specimens sent for histological analysis. Hospitals submitting > 75-100% of the gallbladder specimens had significantly more IGBC/1000 cholecystectomies performed (p = 0.003). Hospitals with the most selective approach had a significantly higher proportion of IGBC/1000 gallbladders that were sent for histological analysis (p < 0.001). Factors such as higher age (p < 0.001), female gender (p = 0.048) and macroscopic cholecystitis (p < 0.001) were more common in gallbladder specimens from hospitals that had a selective approach to histological analysis. A routine approach to histological analysis in cholecystectomies with a benign indication for surgery can uncover a higher proportion of IGBC cases. When a selective approach is used, risk factors should be taken into account.