Histological and immunohistochemical evaluation using endoscopic ultrasound-guided fine-needle aspiration in solid masses

Abstract

s / Pancreatology 13 (2013) S1–S80 S45 Background/aim: Distinguishing pancreatic adenocarcinomas from other pancreatic masses remains challenging in clinical practice. Contrastenhanced harmonic endoscopic ultrasound (CEH-EUS) is a promising method for characterizing pancreatic lesions due to its noninvasiveness. The clinical significance according to the change of enhancement pattern from arterial to venous phaseswas not established. The purpose of this study is to investigate the accuracy of CEH-EUS in the differentiation of pancreatic solid lesions by visualizing enhancement pattern during contrast infusion time. Methods: Between July, 2011 and March, 2013, 116 patients who referred for EUS examination of pancreatic lesions were consecutively enrolled. CEH-EUS was performed with a conventional radial echoendoscope after intravenous bolus injection of contrast agent (SonoVue). Enhancement pattern of target lesion was classified into three groups (hypo-, isoor hyper-enhancement) and also described as contrast injection time; early (10w 30 seconds), late (30w 60 seconds) and delay phase (60 w 90 seconds). The enhancement pattern of pancreatic adenocarcinoma was compared with that of other pancreatic lesions. Results: A total of 83 patients (51 male, median age 68, range 25–91) were evaluated for pancreatic solid lesions. The final diagnoses were pancreatic adenocarcinoma in 63 (75.9%), neuroendocrine tumor in 8 (9.6%), chronic pancreatitis in 3 (3.6%), autoimmune pancreatitis in 3 (3.6%), pancreatic metastasis in 2 (2.4%), malignant lymphoma in 2 (2.4%) and each cases of pancreatic abscess and solid pseudopapillary neoplasm (2.4%). In 63 pancreatic lesions with adenocarcinoma, hypoenhancement during arterial, late and delay phase was observed in 52 (82.5%), 59 (93.7%), and 62 (98.4%), respectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for adenocarcinoma as hypoenhancement at CEH-EUS showed at table 1. Conclusions: CEH-EUS could characterize pancreatic mass lesions with relatively high accuracy during late phase and may be useful for distinguishing adenocarcinomas from other pancreatic masses.