Impact of avascular areas, as measured by contrast-enhanced harmonic EUS, on the accuracy of FNA for pancreatic adenocarcinoma

Background and Aims: EUS-guided FNA (EUS-FNA) is used for the diagnosis of pancreatic adenocarcinoma, but sometimes the method results in a false negative. Occasionally, an avascular area may be observed within the pancreatic adenocarcinoma tumor during contrast-enhanced harmonic EUS (CH-EUS). The aim of this study was to evaluate whether the diagnostic sensitivity of EUS-FNA for pancreatic adenocarcinoma was affected by the presence of avascularity on CH-EUS. Methods: Two hundred ninety-two patients with pancreatic adenocarcinoma who presented at Kindai University Hospital for EUS-FNA and CH-EUS between June 2009 and August 2013 were retrospectively evaluated. This was a single-center retrospective analysis of prospectively collected data held in a registry. The overall sensitivity of EUS-FNA for the diagnosis of pancreatic adenocarcinoma was calculated. The sensitivities of cytology, histology, and the combination of cytology and histology were also evaluated. These variables were individually evaluated according to the presence or absence of an avascular area on CH-EUS to assess whether the diagnostic sensitivity of EUS-FNA for pancreatic adenocarcinoma was related to the presence of an avascular area within the tumors. Results: The overall sensitivity of EUS-FNA was 90.8% (265/292). The sensitivities of EUS-FNA for lesions with and without an avascular area were 72.9% (35/48) and 94.3% (230/244), respectively, with the difference being statistically significant (P <.001). Conclusions: EUS-FNA has lower sensitivity for pancreatic adenocarcinoma with avascular areas on CH-EUS.