Objective: The differential diagnosis of pancreatic solid lesions remains challenging. The aim of this study was to investigate the accuracy of contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) in differentiating pancreatic cancer from benign lesions.

Methods: We prospectively evaluated 37 patients with pancreatic solid lesions. After intravenous injection of a contrast agent (SonoVue), CEH-EUS was performed using a radial echoendoscope. Pancreatic solid lesions were classified into three vascular patterns (hyperintense, isointense, and hypointense) on the basis of CEH-EUS imaging, and these patterns were compared to the histological diagnosis.

Results: The lesions were hypervascular (n=6), isovascular (n=3), or hypovascular (n=28). Histological diagnosis was confirmed by EUS-FNA in 26 patients (22 adenocarcinomas, two focal pancreatitis, one pancreatic neuroendocrine tumor [NET], and one pancreatic tuberculosis); by surgery in 10 patients (four adenocarcinomas, three pancreatic NETs, two invasive intraductal papillary mucinous neoplasms, and one acinar cell carcinoma); and by both methods in one patient. Among pancreatic carcinomas, 28 out of 30 lesions (93%) had persistent hypovascular signals in the early and late phase, which indicates a sensitivity and diagnostic accuracy of 93% and 92%, respectively for the diagnosis of pancreatic cancer.

Conclusions: CEH-EUS was useful for characterization of pancreatic solid masses with high sensitivity and accuracy.