Cholecystectomy is indicated for this patient with a gallbladder polyp and gallstones because of the increased risk for gallbladder cancer when the two conditions coexist. The finding of a gallbladder polyp larger than 1 cm in size is an indication for cholecystectomy, even if the patient is asymptomatic. An additional indication for prophylactic cholecystectomy is the presence of a gallbladder polyp larger than 8 mm in size in the setting of primary sclerosing cholangitis. Gallbladder polyps are found on approximately 5% of ultrasounds. Although only a small percentage of gallbladder polyps are neoplastic (adenoma or adenocarcinoma), the risk for neoplasia increases as polyp size increases.
In a patient with an 8-mm gallbladder polyp in the absence of gallstones or primary sclerosing cholangitis, repeat ultrasonography in 6 months would be indicated. However, follow-up ultrasonography is not appropriate for this patient with a gallbladder polyp and gallstones, which increase the risk for gallbladder cancer.