Role of endoscopic ultrasonography in differential diagnosis of gallbladder wall thickening: a multi-center retrospective study

Background: There are limited data on the usefulness of endoscopic ultrasonography (EUS) in determining malignancy in gallbladder wall thickening. Methods: In this multicenter retrospective study, patients who underwent EUS for gallbladder wall thickening from 2011 to 2021 at seven tertiary hospitals were reviewed. The main outcome was the diagnostic performance of EUS in differentiating gallbladder tumors. Logistic regression analyses were performed to identify key EUS findings. Results: We reviewed 309 patients who underwent EUS for gallbladder wall thickening and excluded 83 patients who did not undergo surgical resection. Among 226 patients who underwent cholecystectomy, 48 patients were diagnosed with gallbladder tumors and 176 patients were diagnosed with benign diseases. EUS showed a sensitivity of 79.31 % and a specificity of 92.86 % for diagnosing gallbladder tumors. Multivariate analysis revealed that wall thickness greater than 14 mm (P < 0.001) and disrupted layer (P < 0.001) were associated with gallbladder tumors. On the other hand, the presence of intramuscular cysts (P = 0.013) and comet tail sign (P = 0.004) were associated with benign diseases. Conclusion: EUS is a useful method for differential diagnosis of gallbladder wall thickening. Wall thickness greater than 14 mm and layer disruption are key findings of gallbladder tumors.