review of literature on clinical pancreatology - The Pancreapedia

mass (n=121) or lymph node (n=101). The classification as benign or malignant, based onthe real time elastography pattern, was compared with the classification based on the B-mode EUS images and with the final diagnosis obtained by EUS-guided fine needleaspiration (EUS-FNA) and/or by surgical pathology. An interobserver study was performed.The sensitivity and specificity <strong>of</strong> EUS elastography to differentiate benign from malignantpancreatic lesions are 92 and 80 percent, respectively, compared to 92 percent and 69percent, respectively, for the conventional B-mode images. The sensitivity and specificity <strong>of</strong>EUS elastography to differentiate benign from malignant lymph nodes was 92 percent and 83percent, respectively, compared to 79 percent and 50 percent, respectively, for the B-modeimages. The kappa coefficient was 0.785 for the pancreatic masses and 0.657 for the lymphnodes. EUS elastography is superior compared to conventional B-mode imaging andappears to be able to distinguish benign from malignant pancreatic masses and lymph nodeswith a high sensitivity, specificity and accuracy. It might be reserved as a second lineexamination to help characterise pancreatic masses after negative EUS-FNA and mightincrease the yield <strong>of</strong> EUS-FNA for lymph nodes [443].MetabolomicsObesity is a worldwide epidemic and a significant risk factor for pancreatic diseases includingpancreatitis and pancreatic cancer; the mechanisms underlying this association areunknown. Metabolomics is a powerful new analytical approach for describing themetabolome (compliment <strong>of</strong> small molecules) <strong>of</strong> cells, tissue or bi<strong>of</strong>luids at any given time.The aim was now to analyze pancreatic fat content in lean and congenitally obese miceusing both metabolomic analysis and conventional chromatography. The pancreatic fatcontent <strong>of</strong> 12 lean (C57BL/6J), 12 obese leptin-deficient (Lep ob ) and 12 obesehyperleptinemic (Lep db ) mice was evaluated by metabolomic analysis, thin-layer and gaschromatography. Pancreata <strong>of</strong> congenitally obese mice had significantly more totalpancreatic fat, triglycerides and free fatty acids, but significantly less phospholipids andcholesterol than those <strong>of</strong> lean mice. Metabolomic analysis showed excellent correlation withthin-layer and gas chromatography in measuring total fat, triglycerides and phospholipids.Differences in pancreatic fat content and character may have important implications whenconsidering the local pancreatic proinflammatory milieu in obesity. Metabolomic analysis is avalid, powerful tool with which to further define the mechanisms by which fat impactspancreatic disease [444].Optical markersPancreatic cancer screening has been hampered by the high rate <strong>of</strong> complicationsassociated with interrogating the pancreas. The closest non-invasively accessible mucosaavailable for pancreatic cancer screening is the periampullary duodenal tissue. An earlierreport has shown the potential <strong>of</strong> using optical markers to interrogate this tissue for thepresence <strong>of</strong> pancreatic cancer. In one study, it was reported a larger data set <strong>of</strong> lowcoherenceenhanced backscattering (LEBS) and elastic light scattering fingerprinting (ELF)optical markers from the periampullary duodenal mucosa. Optical measurements from biopsysamples were acquired from a total <strong>of</strong> 203 patients with varying clinical classificationincluding healthy controls, a family history <strong>of</strong> pancreatic cancer, pancreatitis, mucinous cysticprecursor lesions, pancreatic cancer, and other pancreatic malignancies. Evaluation <strong>of</strong> theperformance <strong>of</strong> an independent testing set for discriminating healthy control patients frompancreatic cancer patients showed a 95 percent sensitivity, 71 percent specificity, and 85percent area under the receiver operator characteristic (AUROC) curve. Importantly, thisperformance was uncompromised for detecting potentially curable stages <strong>of</strong> the disease.Additionally, optical markers in higher risk populations such as family history and pancreatitishad values between those <strong>of</strong> healthy control and pancreatic cancer patients, thus allowing forfuture investigations <strong>of</strong> screening from these high risk groups [445].