Intraductal ultrasonography in diagnosing tumor extension of cancer of the papilla of Vater

Background: Intraductal ultrasonography is clinically useful in assessing various pancreatobiliary diseases. This study was carried out to evaluate the usefulness of intraductal ultrasonography in diagnosing tumor extension of cancer of the papilla of Vater. Methods: Thirty-two patients with cancer underwent intraductal ultrasonography. According to the spatial relationship between the tumor echo and the hypoechoic layers representing Oddi's muscle layer or the duodenal muscularis propria layer, the images were classified into four grades. We attempted to diagnose tumor extension using this grading system. Lymph nodes measuring over 10 mm were evaluated as involved. Findings were compared with postoperative histopathologic findings classified as follows: d0, tumor limited to Oddi's muscle layer; d1, tumor invading the duodenal submucosal layer; d2, tumor invading the duodenal muscularis propria layer; and panc(+), tumor invading the pancreas. Results: Diagnostic accuracy rate was 100% (6 of 6) in d0 cases, 92.3% (12 of 13) in d1 cases, 100% (1 of 1) in a d2 case, and 75% (9 of 12) in panc(+) cases. Overall accuracy rate was 87.5% (28 of 32). In assessing lymph node metastases, sensitivity was 66.7% (6 of 9) and specificity was 91.3% (21 of 23). Conclusion: Intraductal ultrasonography examination is useful in diagnosing tumor extension of cancer of the papilla of Vater.