Prospective comparison of endoscopic ultrasound and endoscopic retrograde cholangiopancreatography in the preoperative assessment of masses in the pancreatic head

Abstract

Aims: To compare the diagnostic value of endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) in the differentiation of malignant from benign masses in the pancreatic head.

Methods: Within 14 months 95 prospective patients with masses in the pancreatic head were assigned for preoperative EUS and ERCP. Both procedures were performed and recorded according to a standardized protocol. Based on intraoperative findings and histology, 50 patients (53%) suffered from malignant and 45 patients (47%) from benign (inflammatory) tumors.

Results: Success rates were 96% for EUS and 95% for ERCP. The overall results for EUS and ERCP to predict malignant masses were, respectively: sensitivity 78 and 81%, specificity 93 and 88%, positive predictive value 93 and 89%, negative predictive value 78 and 80%, and diagnostic accuracy 85 and 84%. When EUS and ERCP were taken together, the sensitivity was 92% (specificity 85%), but the diagnostic accuracy (89%) was not significantly enhanced. The results for EUS to diagnose lymph node metastases preoperatively were: sensitivity 55%, specificity 91%, positive predictive value 69%, negative predictive value 84%, and accuracy 81%.

Conclusions: EUS and ERCP have similar diagnostic accuracies to separate malignant from benign masses in the pancreatic head. Combination of both procedures is not superior to the use of one modality alone. Abnormal lymph nodes visualized on EUS in patients with inflammatory masses in the pancreatic head due to chronic pancreatitis should be interpreted cautiously.