Gallbladder polyps are outgrowths of the gallbladder mucosal wall. They are usually found incidentally on ultrasonography or after cholecystectomy. When detected on ultrasonography, their clinical significance relates largely to their malignant potential. The majority of these lesions are not neoplastic but are hyperplastic or represent lipid deposits (cholesterolosis). Imaging studies alone are insufficiently specific to exclude the possibility of gallbladder carcinoma or premalignant adenomas. Furthermore, even benign lesions can occasionally lead to symptoms similar to those caused by gallbladder stones.
While the widespread use of ultrasonography has made the diagnosis of polypoid lesions of the gallbladder increasingly frequent, optimal strategies for evaluating these lesions have not been fully established. This topic will review the clinical significance and differential diagnosis of gallbladder polyps, and will provide a practical approach to their management. Gallbladder cancer is discussed in detail elsewhere. (See "Gallbladder cancer: Epidemiology, risk factors, clinical features, and diagnosis".)
Gallbladder polyps have been observed in 0.004 to 13.8 percent of resected gallbladders , and in 1.5 to 4.5 percent of gallbladders assessed by ultrasonography [2,3]. In one report, no association was observed between the presence of polyps and the patient's age, sex, weight, number of pregnancies, use of exogenous female hormones, or any other risk factors that are generally believed to be associated with gallstones . Gallbladder polyps have only rarely been described in children, in whom they occur either as a primary disorder or in association with other conditions, including metachromatic leukodystrophy, Peutz-Jeghers syndrome, or pancreatobiliary malunion . (See "Epidemiology of and risk factors for gallstones".)
The classification of gallbladder polyps was first proposed in 1970 based upon a review of 180 benign tumors . As a general rule, polypoid lesions can be categorized as benign or malignant (table 1) [6,7]. Benign lesions have been further subdivided into neoplastic or non-neoplastic:
●The most common benign neoplastic lesion is an adenoma. Benign mesodermal tumors such as leiomyomas and lipomas are rare.