Is endosonography an effective method for detection and local staging of the ampullary carcinoma? A prospective study

BACKGROUND: The relatively rare carcinoma of the ampulla of Vater is a neoplasia with a good prognosis compared to pancreatic cancer. Preoperative staging is important in planning the most suitable surgical intervention. AIM: To prospectively evaluate the diagnostic accuracy of Endoscopic Ultrasonography (EUS) in comparison with conventional US and CT scan, in staging of patients with ampullary carcinoma. PATIENTS AND METHODS: 20 patients (7 women and 13 men) with histologically proven carcinoma of the ampulla of Vater were assessed by EUS, CT scan and US. Results were compared to surgical findings. RESULTS: Endoscopic biopsies were diagnostic in 76% of the patients. Detection of ampullary cancer with US and CT scan was 15% and 20% respectively. Only indirect signs of the disease were identified in the majority of cases using these methods. Overall accuracy of EUS in detection of ampullary tumours was 100%. The EUS was significantly (p < 0.001) superior than US and CT scan in ampullary carcinoma detection. Tumour size, tumour extension and the existence of metastatic lymph nodes were also identified and EUS proved to be very useful for the preoperative classification both for the T and the N components of the TNM staging of this neoplasia. The diagnostic accuracy for tumour extension (T) was 82% and for detection of metastatic lymph nodes (N) was 71%. CONCLUSION: EUS is more accurate in detecting ampullary cancer than US and CT scan. Tumor extension and locally metastatic lymph nodes are more accurately assessed by means of EUS than with other imaging methods.