AB038. 215. Ultrasound detection of polypoid lesions of the gallbladder

Background: Gallbladder polyps are most often diagnosed as an incidental finding on routine abdominal ultrasound, or following cholecystectomy for gallstone disease. Current guidelines recommend that cholecystectomy be performed for gallbladder polyps >10 mm due to the risk of progression to gallbladder cancer, while management of polyps <10 mm depends on patient and polyp characteristics. This single centre study sought to assess the sensitivity of ultrasonography in the detection of gallbladder polyps.

Methods: All patients undergoing cholecystectomy for gallbladder polyps detected on ultrasound over a 3-year study period from November 2014 to November 2017 were included. Patients in whom incidental polyps were identified on histological analysis were not eligible for inclusion.

Results: Of the 276 patients who underwent cholecystectomy over the study period, 29 (10.5%) did so for polyps detected on ultrasound. The average polyp size was 9.4 mm. Of these 29 patients, 20 (69%) did not have evidence of gallbladder polyps on histological analysis. Of the nine patients in whom polyps were detected, six were identified as having cholesterol polyps. One hyperplastic polyp was identified, and two patients were found to have adenocarcinoma of the gallbladder. Of the 20 patients in whom gallbladder polyps were not identified, gallstones were found in 10. The size of polyp on ultrasound was not predictive of a positive finding on histology.

Conclusions: The majority of patients who underwent cholecystectomy for gallbladder polyps were subsequently found not to have polyps on histological analysis. This study questions the efficacy of ultrasonography in accurately detecting polypoid lesions of the gallbladder.

Keywords: Gallbladder; polyp; ultrasound; detection