Objective: To evaluate the diagnostic efficacy of transabdominal sonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and endosonography (EUS) in ampullary tumors.
Methods: Accuracy was assessed with TNM staging and compared with the histopathology in 41 consecutive ampullary tumors.
Results: The detection rate for ampullary tumor was 97.6% for EUS, 81.3% for MRI, 28.6% for CT, and 12.2% for US (p< 0.001 for EUS vs. CT; p< 0.001 for EUS vs. US; p> 0.05 for EUS vs. MRI). The accuracy in T staging for ampullary carcinoma was 72.7% for EUS, 53.8% for MRI, and 26.1% for CT (p< 0.01 for EUS vs. CT; p> 0.05 for EUS vs. MRI). The accuracy in N staging for ampullary carcinoma was 66.7% for EUS, 76.9% for MRI, and 43.5% for CT with no statistically significant difference between the three modalities. The sensitivity in detecting malignant lymph node was 46.7% for EUS, 25.0% for MRI, and 0.0% for CT (p < 0.01 for EUS vs. CT; p > 0.05 for EUS vs. MRI; p > 0.05 for MRI vs. CT). Transpapillary stenting, advanced tumor extension (> T2), large tumor size (> 2 cm), tumor differentiation, and endoscopic appearance of tumor growth did not significantly influence endosonographic T or N staging accuracy (p > 0.05).
Conclusions: EUS was superior to CT for tumor detection, T staging, and detecting lymph node metastasis of ampullary tumors, and it was equivalent to MRI. Neither indwelling stents nor tumor nature affected the staging accuracy of EUS.