Polypoid tumors of the major duodenal papilla: preoperative staging with intraductal US, EUS, and CT--a prospective, histopathologically controlled study.

BACKGROUND: An adenoma-carcinoma sequence also applies to adenomas of the major duodenal papilla. Therefore accurate preoperative diagnosis and tumor staging are essential to select the appropriate patients for adequate treatment. In a prospective, histopathologically controlled study of tumors of the main duodenal papilla, the preoperative diagnostic value of ultrasound (US) catheter probes applied during endoscopic retrograde cholangiopancreatography (ERCP) was investigated.

METHODS: Intraductal US was compared with conventional endoscopic ultrasonography (EUS) and computed tomography (CT). In 27 consecutive patients with benign polypoid tumors of the major duodenal papilla (n = 12) and carcinomas of the papilla (n = 15), respectively, the value of these imaging procedures in determining tumor visualization, tumor diagnosis and tumor staging according to the TNM classification was assessed. Every patient underwent surgical resection; histopathologic evaluation of resected specimens served as the reference standard.

RESULTS: Intraductal US was significantly superior to EUS and CT in terms of tumor visualization (100% vs 59.3% vs 29.6%, respectively). Sensitivity and specificity rates for intraductal US and EUS were 100% versus 62.5% and 75% versus 50%, respectively. Overall accuracy rate in tumor diagnosis for intraductal US (88.9%; 24 of 27) was significantly (p = 0.05) superior to EUS (56.3%; 9 of 16). The latter did not depict 4 adenomas and 7 carcinomas. Neither intraductal US nor EUS is suitable for detection of distant metastases.

CONCLUSION: Intraductal US appears to be the most effective imaging method in visualizing, diagnosing and staging tumors of the major duodenal papilla. Combining ERCP with catheter probe sonography offers a new diagnostic modality that has some potential advantages for local staging of small tumors of the main duodenal papilla. Consequently, minimally invasive techniques for resection of seemingly benign tumors of the papilla or, even more so, of small carcinomas should preferably be based on intraductal US.