Endoscopic ultrasonography can differentiate neoplastic from
Although most gallbladder (GB) polyps are benign, some early carcinomas of the GB share the same appearance as benign polyps. Currently, GB polyps larger than 1 cm should be surgically removed because of the increased risk of malignancy. On the other hand, patients with smaller polyps usually require repeated US and follow-up. Distinguishing among non-neoplastic, neoplastic, and potentially malignant lesions is a major diagnostic dilemma, and the therapeutic options for these lesions remain controversial. A research article to be published in May 21, 2009 in the World Journal of Gastroenterology addresses this question.
EUS is considered to be superior to conventional US for imaging GB lesions, because EUS can provide high-resolution images of small lesions at higher ultrasound frequencies (7.5-12 MHZ vs 3.5-5 MHz). Many studies have investigated the relationship between the neoplastic nature of GB polyps and their morphological characteristics such as the number of polyps, the polyp shape, the diameter of the largest polyp, the echo level and internal echo pattern, and the polyp margin. Among these variables, size is the most significant predictor of neoplastic polyps.
EUS could not differentiate malignant lesions from benign polyps less than 1.0 cm in size, because such small polyps do not often show findings typical of cholesterol polyps, localized types of adenomyomatosis, or neoplastic lesions. Thus, EUS alone is not sufficient for determining a treatment strategy for benign polypoid lesion of less than 1.0 cm.