Background: EUS is a precise method for detection and staging of pancreatic tumors. However, differentiation between inflammatory pseudotumor and pancreatic carcinoma remains difficult. The aim of this study was to evaluate contrast-enhanced EUS as a method of differentiating inflammation and carcinoma based on perfusion characteristics.
Methods: Patients with solid pancreatic masses underwent EUS with a linear echoendoscope. Perfusion in the pancreatic tissue and the mass was assessed with native and contrast-enhanced EUS with power- and color-Doppler imaging. Examinations were evaluated by a blinded reader. A markedly hyperperfused lesion was considered an inflammatory pseudotumor whereas lesions that were hypoperfused compared with surrounding tissue were considered to be carcinoma.
Results: Fifteen of 23 patients had hypoperfusion within the mass and 8 patients had hyperperfused lesions. Of the 15 patients with hypoperfused masses, all had pancreatic adenocarcinoma; 1 of 8 patients with a hyperperfused lesion also had adenocarcinoma. The remaining 7 patients had focal inflammation. Sensitivity for differentiation of pancreatic carcinoma versus inflammatory changes was 94%, specificity 100%.
Conclusion: Echo-enhanced power-Doppler EUS reliably differentiates pancreatic neoplasm and focal pancreatitis. The diagnostic accuracy of this technique is comparable to CT, magnetic resonance imaging, positron emission tomography, and ERCP.