What are gallbladder polyps and how are they managed?

From the Guidelines

Gallbladder polyps are abnormal growths that protrude from the inner lining of the gallbladder wall, with most being non-cancerous and not requiring treatment, particularly if they're smaller than 10mm. The management of gallbladder polyps depends on their size and the patient's risk factors. Some key points to consider include:

• The size of the polyp: polyps smaller than 10mm are generally considered low risk, while those larger than 10mm are considered higher risk 1.
• The patient's risk factors: patients with a history of gallstones, primary sclerosing cholangitis, or age over 50 are considered higher risk 1.
• The type of polyp: neoplastic polyps are more likely to be malignant than nonneoplastic polyps 1.
• The growth rate of the polyp: rapid growth is considered a concerning feature, although the exact definition of rapid growth is not well established 1.

In terms of management, watchful waiting with follow-up ultrasounds every 6-12 months is typically recommended for polyps smaller than 10mm without concerning features. For polyps larger than 10mm, those that grow during surveillance, or in patients with risk factors for gallbladder cancer, cholecystectomy (surgical removal of the gallbladder) is generally advised 1. The surgery is usually performed laparoscopically as an outpatient procedure, and patients can typically return to normal activities within 1-2 weeks after surgery. No medications specifically treat gallbladder polyps, although addressing underlying conditions like hyperlipidemia may help with cholesterol polyps. Regular follow-up is essential for conservative management to monitor for any changes in polyp size or characteristics that might warrant surgical intervention 1.

It's worth noting that the incidence of gallbladder cancer is rare, but lethal, and that most gallbladder polyps are not malignant 1. However, it's still important to monitor polyps closely and consider surgical removal if they are large or if the patient has risk factors for gallbladder cancer.

Some studies have shown that the risk of malignancy increases with the size of the polyp, with polyps larger than 10mm having a higher risk of malignancy 1. Other studies have shown that the type of polyp, with neoplastic polyps being more likely to be malignant than nonneoplastic polyps, is also an important factor in determining the risk of malignancy 1.

Overall, the management of gallbladder polyps should be individualized based on the patient's risk factors and the characteristics of the polyp. A thorough evaluation and monitoring plan should be developed for each patient, taking into account the latest evidence and guidelines 1.

From the Research

Definition and Classification of Gallbladder Polyps

• Gallbladder polyps are elevations of the gallbladder mucosa that protrude into the gallbladder lumen 2, 3.
• They can be divided into neoplastic (true) polyps and nonneoplastic polyps (pseudopolyps) 2.
• Nonneoplastic polyps include cholesterol polyps, focal adenomyomatosis, and inflammatory polyps, which have no malignant potential 2, 3.
• Neoplastic polyps can be benign (adenomas) or malignant (adenocarcinoma) 2.

Causes and Risk Factors of Gallbladder Polyps

• The exact causes of gallbladder polyps are not well understood, but they are thought to be related to impaired cholesterol metabolism, gallbladder cholesterosis, metabolic syndrome, and cardiovascular morbidity 3.
• Risk factors for malignancy in gallbladder polyps include age over 60 years, history of primary sclerosing cholangitis, Asian ethnicity, and sessile polypoid lesions 4.

Diagnosis and Management of Gallbladder Polyps

• Transabdominal ultrasonography is the main radiological modality used for diagnosing and surveilling gallbladder polyps 2.
• Cholecystectomy is recommended for polypoid lesions of the gallbladder measuring 10 mm or more, or for those with risk factors for malignancy 4.
• Follow-up ultrasound is recommended for patients with gallbladder polypoid lesions of 6-9 mm and no risk factors for malignancy, or for those with risk factors and lesions of 5 mm or less 4.
• Ursodeoxycholic acid preparations may be useful in managing cholesterol polyps and reducing the risk of cardiovascular disease 3.

Genetic Epidemiology of Gallbladder Stones

• Gallstone disease has a strong genetic component, with multiple environmental influences and common genetic factors contributing to its formation 5.
• Distinct common gene variants may contribute to gallstone formation in different ethnic groups, and the characterization of lithogenic genes in mice may provide insights into the development of new strategies for individual risk assessment and prevention 5.