Frequency, Risk Factors, and Outcome of Gallbladder Polyps in Patients With Primary Sclerosing Cholangitis: A Case-Control Study.

The prevalence polyps (GBPs) in the general population has been estimated to be approximately 5%, with up to 10% of these being dysplastic or malignant. Previous studies have suggested that patients with primary sclerosing cholangitis (PSC) have increased frequency of GBPs. However, data on the prevalence, risk factors, and outcome of GBPs in these patients are sparse. This case-control study investigates the frequency, risk factors, and outcome of GBPs in patients with PSC. In this study, 363 patients with an established diagnosis of PSC based on magnetic resonance cholangiopancreatography (MRCP), endoscopic retrograde cholangiopancreatography (ERCP), or liver biopsy were identified. Patients with at least one abdominal imaging and no history of cholecystectomy before the first available abdominal imaging were included. The presence of GBPs was confirmed by abdominal computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound. Patients with GBPs were compared to those without GBPs. Furthermore, patients with malignant/premalignant polyps were compared to those with benign polyps. The frequency of GBPs in patients with PSC was 10.6%. There was no significant difference in the frequency of inflammatory bowel disease (IBD) between the two groups. Of the 16 with GBPs who underwent cholecystectomy, 10 had malignant/premalignant lesions, of whom 6 had adenocarcinoma, and 4 had high-grade dysplasia. Of the 6 patients with adenocarcinoma, 4 had lesions >10 mm, 1 had a lesion as small as 4 mm, and 1 had a 7-mm lesion. Conclusion: GBPs may be frequently seen in patients with PSC. These lesions seem to occur independent of IBD. In patients with PSC, even small GBPs appear to have a risk of malignancy. These findings suggest that patients with PSC and GBPs may benefit from cholecystectomy, regardless of the size of the polyp.