Objective:

To analyze the accuracy of endoscopic ultrasound (EUS) in the evaluation of ampullary tumors compared to histopathology (HP) staging.

Methods:

A retrospective diagnostic test study. Patients with ampullary tumors staged by EUS and postpancreatoduodenectomy HP attended during 2012-2018 at tertiary level hospital.

Results:

14 patients with adenocarcinoma where included. Tumor size measured by EUS showed an adequate correlation (R = 0.65; p= 0.01) with HP. The accuracy in the evaluation of duodenal wall, pancreatic, and biliary duct invasion was 78.5, 78.5 and 57.1%, respectively. By HP, there were three T1 (21.4%), two T2 (14.2%) and nine T3 (64.2%). The accuracy of T and N staging by EUS was 71.4% (kappa = 0.50) and 50% (kappa = −0.04) respectively. There were more staging errors in patients with biliary stent.

Conclusion:

EUS was useful in estimating tumor size, duodenal wall and pancreatic invasion. Limitation was found in the evaluation of biliary duct invasion, as well as overestimation of T stage and underestimation of N stage. It is necessary an increased effort in ultrasonography training. We suggest EUS testing before biliary stenting.