Background : Gallbladder polyps are a relatively common indication for cholecystectomy. Occasionally, gallbladder cancer is diagnosed after cholecystectomy. This study evaluated whether the size and shape of gallbladder polyps can predict gallbladder cancer.

Methods : This single-center, retrospective study included 390 patients who underwent laparoscopic cholecystectomy for gallbladder polyp between May 2001 and August 2023. We evaluated the gallbladder polyp size and morphology on preoperative imaging studies.

Results : Of 390 patients (mean age, 52.9 years; 215 [55.1%] women), 17 (4.4%) were diagnosed with gallbladder cancer after cholecystectomy. Malignant lesions were statistically significant larger than benign lesion (9.7 mm vs. 14.9mm, p <0.001). The detection rate of gallbladder cancer increased with increasing polyp size: 3.3% for polyps 10-12 mm in size, 15.9% for polyps 13-19 mm in size, and 25% for polyps 20-30 mm in size. Patients with malignant lesions were significantly older than those with benign lesions (52.2 years vs. 67.6 years, p <0.001). In Receiver operating characteristic curve analyses, the cutoff values for polyp size and age were calculated to be 13.5 mm and 60.5 years, respectively The sessile morphology (4.0% vs. 82.4%, p <0.001) and ill-defined margin (4.6% vs. 17.6%, p = 0.017) were significantly more frequent in malignant than benign lesions. In multivariate analysis, sessile morphology and polyp size ≥ 14 mm were statistically significant predictors of gallbladder cancer.

Conclusions : This study demonstrated that sessile and large (≥ 14 mm) gallbladder polyp on preoperative imaging should be considered for the possibility of gallbladder cancer.