A 65-year-old man is evaluated after a screening ultrasound for abdominal aortic aneurysm showed incidental gallbladder findings. He reports no symptoms. He continues to smoke cigarettes, 1 pack per day. He has no other medical problems and takes no medications.
On physical examination, vital signs are normal, as is the remainder of the examination.
The results of all laboratory studies, including a complete blood count and alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels, are within normal limits.
The abdominal ultrasound shows numerous layering gallstones and an immobile 8-mm gallbladder polyp.
Which of the following is the most appropriate next step in management?
B. MR cholangiopancreatography
C. Repeat ultrasonography in 6 months
D. Ursodeoxycholic acid
MKSAP Answer and Critique
The correct answer is A. Cholecystectomy. This content is available to MKSAP 18 subscribers as Question 18 in the Gastroenterology and Hepatology section. More information about MKSAP is available online.
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.
Further evaluation of the polyp with abdominal CT, endoscopic retrograde cholangiopancreatography, or MR cholangiopancreatography is not indicated because gallbladder ultrasonography is adequately sensitive for the detection of gallbladder lesions. These tests could be considered if this patient had symptoms or elevated liver chemistry tests suggesting bile-duct obstruction or malignancy.
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.
Bile acids, such as ursodeoxycholic acid, work by reducing biliary cholesterol secretion, thereby increasing biliary bile-acid concentrations and, as a result, reducing the cholesterol saturation index and gallstone size. Bile-acid therapy works best for small, primarily cholesterol gallstones and is indicated in patients who cannot or will not undergo laparoscopic cholecystectomy. More importantly, ursodeoxycholic acid therapy would not address this patient's gallbladder polyp.
- The finding of a gallbladder polyp larger than 1 cm in size, or a polyp of any size associated with gallstones, is an indication for cholecystectomy even if the patient is asymptomatic.