Effectiveness of contrast-enhanced endoscopic ultrasound for detecting mural nodules in intraductal papillary mucinous neoplasm of the pancreas and for making therapeutic decisions

Abstract

Background and Objectives:There have been few studies to date evaluating the effectiveness of contrast-enhanced endoscopic ultrasound (CE-EUS) for detecting mural nodules in patients with branch duct-type intraductal papillary mucinous neoplasm (BD-IPMN) of the pancreas. We aim to evaluate the effectiveness of CE-EUS for detecting mural nodules in BD-IPMN.Patients and Methods:Of the 427 BD-IPMN patients, 21 patients (4.9%) in whom the presence of mural nodules was suggested by CE computed tomography (CT) or magnetic resonance imaging (MRI), or in whom the presence of nodule-like lesions as shown by fundamental EUS, were examined by CE-EUS.Results:The mean diameter of cystic lesions was 29.8 ± 12.8 mm. The mean diameter of mural nodules was 9.5 ± 5.7 mm. BD-IPMN was detected in the pancreatic head in 16 cases, pancreatic body in 2 cases, and pancreatic tail in 3 cases. The mean follow-up period was 17.2 ± 11.9 months. The detection rates of mural nodule-like lesions in BD-IPMN patients on CT, MRI, and fundamental EUS were 36.8%, 63.2%, and 100%, respectively. The detection rates of true mural nodules in BD-IPMN patients on CT, MRI, and fundamental EUS were 85.7%, 71.4%, and 100%, respectively. The echo levels of mural nodule-like lesions on fundamental EUS were hyperechoic in 6 patients, isoechoic in 9 patients, and hypoechoic in 6 patients. The final diagnosis was mucus lumps in 14 patients and mural nodules in 7 patients. The contrast patterns observed were avascular, isovascular, and hypervascular in 14, 3, and 4 patients, respectively. No patients showed a hypovascular pattern. Fourteen patients showing an avascular pattern were diagnosed as having mucus lumps, and they were able to avoid surgical resection. Of the 7 patients who were diagnosed as having mural nodules, 5 underwent surgical resection. The pathological findings were adenocarcinoma in 2 patients and adenoma in 3 patients. Of the 3 adenoma patients, fundamental EUS demonstrated a hypoechoic area in 1 patient and an isoechoic area in 2 patients. Of the 2 adenocarcinoma patients, 1 each showed a hypoechoic area and a hyperechoic area. It was difficult to distinguish between patients with adenoma and patients with adenocarcinoma using the echo levels obtained from fundamental EUS.Conclusions:CE-EUS may be useful for avoiding the overdiagnosis of BD-IPMN with mural nodule-like lesions. However, it has difficulty in distinguishing between clearly benign and malignant lesions in BD-IPMN.

An Extragastrointestinal Stromal Tumor Originating from the Pancreas

“…Even for benign lesions like in our case, after obtaining sufficient cells by repeated fine-needle aspiration, immunochemical staining can improve the diagnostic accuracy and differential diagnosis [ 13 ]. In addition, CE-EUS proved to be a useful technique for differential diagnosis of solid lesions of the pancreas [ 14 , 15 ]. It is known that CE-EUS pattern can distinguish pancreatic disease [ 15 , 16 , 17 , 18 , 19 , 20 ].…”

Impact of endoscopic ultrasonography on diagnosis of pancreatic cancer

“…Harima et al [ 92 ] reported that the sensitivity and specificity of EUS were 100% and 61%, respectively, while those of CT were 71% and 100%. The sensitivity of CT in comparison with EUS has also been reported to be as low as 24–37% [ 91 , 94 ].…”

“…The sensitivity of CT in comparison with EUS has also been reported to be as low as 24–37% [ 91 , 94 ].…”

New horizons in the endoscopic ultrasonography-based diagnosis of pancreatic cystic lesions

“…Comparable results were found in later studies. Fujita et al[ 40 ] observed that CT, MRI, and EUS detected mural nodules histologically confirmed in 86%, 71% and 100% of cases. Although EUS was highly sensitive, it was not able to distinguish mucous clots from mural nodules that were correctly classified in all cases after assessing the vascular pattern by CH-EUS (Figure 1 ).…”