Needle-based confocal laser endomicroscopy in pancreatic cysts : a meta-analysis

The prevalence of pancreatic cysts is not known, but asymptomatic pancreatic cysts are diagnosed with increasing frequency. We investigated the prevalence of pancreatic cysts in individuals who were screened by magnetic resonance imaging (MRI) as part of a preventive medical examination. Data from consecutive persons who underwent abdominal MRI (n = 2803; 1821 men; mean age, 51.1 +/- 10.8 y) at an institute of preventive medical care were included from a prospective database. All individuals had completed an application form including questions about possible abdominal complaints and prior surgery. MRI reports were reviewed for the presence of pancreatic cysts. Original image sets of all positive MRI reports and a representative sample of the negative series were re-assessed by a blinded, independent radiologist. Pancreatic cysts were reported in 66 persons (2.4%; 95% confidence interval, 1.9-3.0); prevalence correlated with increasing age (P < .001). There was no difference in prevalence between sexes (P = .769). There was no correlation between abdominal complaints and the presence of pancreatic cysts (P = .542). Four cysts (6%) were larger than 2 cm and 3 (5%) were larger than 3 cm. Review of the original image sets by the independent radiologist did not significantly change these findings. The prevalence of pancreatic cysts in a large consecutive series of individuals who underwent an MRI at a preventive medical examination was 2.4%. Prevalence increased with age, but did not differ between sexes. Only a minority of cysts were larger than 2 cm. Copyright 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

Pancreatic cystic tumors commonly include serous cystadenoma (SCA), mucinous cystadenoma (MCA), and mucinous cystadenocarcinoma (MCAC). A differential diagnosis with pseudocysts (PC) can be difficult. Radiologic criteria are not reliable. The objective of the study is to investigate the value of cyst fluid analysis in the differential diagnosis of benign (SCA, PC) vs. premalignant or malignant (MCA, MCAC) lesions. A search in PubMed was performed with the search terms cyst, pancrea, and fluid. Articles about cyst fluid analysis of pancreatic lesions that contained the individual data of at least 7 patients were included in the study. Data of all individual patients were combined and were plotted in scatter grams. Cutoff levels were determined. Twelve studies were included, which comprised data of 450 patients. Cysts with an amylase concentration 800 ng/mL strongly suggested MCA or MCAC (sensitivity 48%, specificity 98%). A carbohydrate-associated antigen (CA) 19-9 <37 U/mL strongly suggested PC or SCA (sensitivity 19%, specificity 98%). Cytologic examination revealed malignant cells in 48% of MCAC (n = 111). Most pancreatic cystic tumors should be resected without the need for cyst fluid analysis. However, in asymptomatic patients, in patients with an increased surgical risk, and, in patients in whom there is a diagnostic uncertainty about the presence of a PC, cyst fluid analysis helps to determine the optimal therapeutic strategy.

Objective DNA-based testing of pancreatic cyst fluid (PCF) is a useful adjunct to the evaluation of pancreatic cysts (PCs). Mutations in KRAS/GNAS are highly specific for intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs), while TP53/PIK3CA/PTEN alterations are associated with advanced neoplasia. A prospective study was performed to evaluate preoperative PCF DNA testing. Design Over 43-months, 626 PCF specimens from 595 patients were obtained by endoscopic ultrasound (EUS)-fine needle aspiration and assessed by targeted next-generation sequencing (NGS). Molecular results were correlated with EUS findings, ancillary studies and follow-up. A separate cohort of 159 PCF specimens was also evaluated for KRAS/GNAS mutations by Sanger sequencing. Results KRAS/GNAS mutations were identified in 308 (49%) PCs, while alterations in TP53/PIK3CA/PTEN were present in 35 (6%) cases. Based on 102 (17%) patients with surgical follow-up, KRAS/GNAS mutations were detected in 56 (100%) IPMNs and 3 (30%) MCNs, and associated with 89% sensitivity and 100% specificity for a mucinous PC. In comparison, KRAS/GNAS mutations by Sanger sequencing had a 65% sensitivity and 100% specificity. By NGS, the combination of KRAS/GNAS mutations and alterations in TP53/PIK3CA/PTEN had an 89% sensitivity and 100% specificity for advanced neoplasia. Ductal dilatation, a mural nodule and malignant cytopathology had lower sensitivities (42%, 32% and 32%, respectively) and specificities (74%, 94% and 98%, respectively). Conclusions In contrast to Sanger sequencing, preoperative NGS of PCF for KRAS/GNAS mutations is highly sensitive for IPMNs and specific for mucinous PCs. In addition, the combination of TP53/PIK3CA/PTEN alterations is a useful preoperative marker for advanced neoplasia.