Published online Jan 14, 2014. doi: 10.3748/wjg.v20.i2.518
Revised: October 25, 2013
Accepted: November 12, 2013
Published online: January 14, 2014
AIM: To evaluate the usefulness of contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) in differentiating between pancreatic adenocarcinomas and other pancreatic disease.
METHODS: This retrospective cohort study evaluated 90 patients who were seen between November 2010 and May 2013. All these patients had solid pancreatic masses that had a hypoechoic appearance on EUS. All patients underwent CH-EUS to evaluate this diagnostic method’s usefulness. The mass lesions observed on CH-EUS were classified into three categories based on their echo intensity: hypoenhanced, isoenhanced, and hyperenhanced lesions. We adjusted the sensitivity and the specificity of each category for detecting malignancies. We also estimated the accuracy of CH-EUS by comparing it to a pathological diagnosis.
RESULTS: Of the 90 patients, 62 had a pancreatic adenocarcinoma. Fifty-seven out of 62 pancreatic adenocarcinomas showed a hypoenhanced pattern on CH-EUS. The sensitivity was 92%, the specificity 68% and the accuracy approximately 82%. The area under the curve of the receiver operating characteristic analysis for CH-EUS was 0.799. There is a significant association between the hypoenhanced pattern on CH-EUS and pancreatic duct adenocarcinoma (χ2 = 35.264, P < 0.001). In pathological examinations, the number of specimens for EUS-fine needle aspiration (EUS-FNA) was considered insufficient for diagnosis in three patients, and in two patients, the results were reported to be negative for malignancy. Pancreatic masses in all five patients revealed a hypoenhanced pattern with CH-EUS. Three patients were diagnosed with pancreatic adenocarcinoma based on the pathology results of a biopsy, and the remaining two patients were clinically diagnosed with malignancy.
CONCLUSION: CH-EUS is useful for distinguishing between pancreatic adenocarcinoma and other pancreatic disease. When a pancreatic mass shows a hypoenhanced pattern on CH-EUS but involves either insufficient samples or negative results with EUS-FNA, clinicians might consider performing another pathologic diagnosis on the basis of an EUS-FNA sample or a biopsy.
Core tip: This is a retrospective study of 90 patients with a pancreatic hypoechoic masses. We found that contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) can be used for distinguishing between pancreatic adenocarcinoma (n = 62) and other pancreatic disease based on the hypoenhanced pattern on CH-EUS. When considering pancreatic adenocarcinomas as a tumor with a hypoenhanced pattern in CH-EUS and/or showing a positive result in EUS-fine needle aspiration, the sensitivity of detecting pancreatic malignancy increased to 100%.