Background: The goal of the preoperative workup in patients with suspected periampullary carcinoma is to establish the diagnosis with a high degree of certainty. In this study we compared endoscopic ultrasonography (EUS) and computed tomography (CT) scans for the detection of tumor, lymph node metastasis, and vascular invasion in patients with suspected periampullary carcinoma in order to define a role for EUS in the preoperative staging of these patients.

Methods: Thirty-seven consecutive patients received EUS and CT scanning followed by operation for presumed periampullary carcinoma during a 30-month period. Both imaging modalities were reviewed in a blinded fashion and the results compared with pathology and operative reports on all patients.

Results: Sensitivity, specificity, positive predictive value, and negative predictive value for tumor detection by EUS were 97%, 33%, 94%, and 50%, respectively, compared with 82%, 66%, 97%, and 25% for CT scan. For lymph nodes the values were 21%, 80%, 57%, and 44%, respectively, for EUS compared with 42%, 73%, 67%, and 50% for CT. For vascular invasion, the values were 20%, 100%, 100%, and 89%, respectively, for EUS, compared with 80%, 87%, 44%, and 96% for CT.

Conclusions: CT is the initial study of choice in patients with suspected periampullary tumors. EUS is superior for detecting tumor and for predicting vascular invasion. Therefore, EUS should be used for patients in whom CT does not detect a mass and for those with an identifiable mass on CT in whom vascular invasion cannot be ruled out.