The Accuracy of Endoscopic Ultrasound, Endoscopic Retrograde Cholangiopancreatography, Computed Tomography, and Transabdominal Ultrasound in the Detection and Staging of Primary Ampullary Tumors

Background/aims: To compare the accuracy between EUS (endoscopic ultrasound), ERCP (endoscopic retrograde cholangiopancreatography), CT (computed tomography), and transabdominal US (ultrasound) in the detection and staging of primary ampullary tumors. We will also try to discuss the influence of endobiliary stent on EUS in staging ampullary tumors.

Methodology: Twenty-one patients with ampullary tumors were evaluated by EUS, ERCP, CT, and US before operation. The accuracy was assessed with TNM staging and compared with the surgical-pathological findings.

Results: EUS was superior to CT and US in detecting ampullary tumors, but EUS and ERCP are of similar sensitivity (EUS 95%, ERCP 95%, CT 19%, US 5%). EUS was superior to CT and US in T staging (EUS 75%, CT 5%, US 0%) and detecting lymph node metastasis (EUS 50%, CT 33%, US 0%) of ampullary tumors. The accuracy of EUS in T and N staging of ampullary tumors tended to be decreased in the presence of endobiliary stent (stenting: T 71%, N 75%; nonstenting T 83%, N 100%), but there was no statistical significance.

Conclusions: EUS was superior to CT and US in assessing primary ampullary tumors, but it was not significantly superior to ERCP in detecting ampullary tumors. The presence of endobiliary stent may decrease the accuracy of EUS in staging ampullary tumors.