Background: Recent European multisociety guidelines recommend routine follow-up imaging of gallbladder polyps (including polyps <6 mm in patients without risk factors) and size change of =2 mm to prompt cholecystectomy. Objective: To assess longitudinal changes in the number and size of gallbladder polyps on serial ultrasound examinations. Methods: This retrospective study included patients who underwent at least one screening ultrasound examination between January 2010 and December 2020 as part of a hepatocellular carcinoma screening and surveillance program that demonstrated a gallbladder polyp. Number of polyps and size of largest polyp were recorded based primarily on review of examination reports. Longitudinal changes on serial examinations were summarized. Pathologic findings from cholecystectomy were reviewed. Results: Among 9683 patients, 759 (8%) had at least one ultrasound examination showing a polyp. Of these, 434 patients (248 male, 186 female; mean age, 50.6 years) had multiple examinations (range, 2-19 examinations; mean 4.8 examinations per patient; mean interval between first and last examinations of 3.6 ± 3.1 years, maximum 11.0 years). Among these 434 patients, 257 had one polyp, 40 had two polyps, and 137 had more than 2 polyps. Polyp size was =6 mm in 368 patients, 7-9 mm in 52 patients, and =10 mm in 14 patients. Number of polyps increased in 9%, decreased in 14%, both increased and decreased on serial examinations in 22%, and showed no change in 55%. Polyp size increased in 10%, decreased in 16%, both increased and decreased on serial examinations in 18%, and showed no change in 56%. In 9% of patients, gallbladder polyps were not detected on follow-up imaging; in 6% of patients, gallbladder polyps were not detected on a follow-up examination but then detected on later studies. No gallbladder carcinoma was identified in nineteen patients who underwent cholecystectomy. Conclusion: Gallbladder polyps fluctuate in size, number, and visibility over serial examinations. Using 2 mm threshold for growth, 10% increased in size. No carcinoma was identified. Clinical Impact: Recent European multisociety guidelines that propose surveillance of essentially all polyps and a 2 mm size change as basis for cholecystectomy are likely too conservative for clinical application.
View details for DOI 10.2214/AJR.21.26614
View details for PubMedID 34549608