Background: Endoscopic papillectomy is performed in selected patients with ampullary neoplasm, and, thus, accurate preoperative tumor staging is indispensable for its application.
Design: Prospective and histopathologically controlled study.
Setting: Single center.
Patients and interventions: EUS and transpapillary intraductal US (IDUS) were performed in 40 patients with ampullary neoplasm before surgery (n = 30) or endoscopic papillectomy (n = 10). Ductal infiltration by a tumor into the bile duct (BD) or the pancreatic duct (PD) was also evaluated. The indication for endoscopic papillectomy was determined by findings obtained by EUS and IDUS. These findings were compared with histologic features of the resected specimens.
Main outcome measurements and results: Thirty-three patients had adenocarcinoma (14 pT1, 11 pT2, 8 pT3-4) and 7 had adenoma. Tumor depiction by EUS and IDUS was achieved in 95% and 100% of the patients, respectively. The diagnostic accuracy of EUS and IDUS in T staging was 62% and 86% in adenoma and pT1, 45% and 64% in pT2, and 88% and 75% in pT3-4, respectively. The overall accuracy by EUS and IDUS in T staging was 63% and 78%, respectively (P = .14). In 10 patients who underwent endoscopic papillectomy, the accuracy of IDUS in T staging with EUS and IDUS was 80% and 100%, respectively. Ductal infiltration into the BD and the PD was correctly assessed in 88% and 90% by EUS and in both BD and the PD in 90% by IDUS, respectively. Ductal infiltration was correctly diagnosed by EUS and IDUS in all patients who had a papillectomy.
Conclusion: Although IDUS had a tendency of overestimation in tumor staging for ampullary neoplasm, it can provide useful information for making therapeutic decisions, especially in cases appropriate for endoscopic papillectomy.