Second-generation endoscopic ultrasound elastography in the differential diagnosis of solid pancreatic masses. Pancreatic cancer vs. inflammatory mass in chronic pancreatitis.

Endoscopic ultrasonography (EUS) is considered one of the most accurate methods for the diagnosis and staging of pancreatic tumors. EUS-guided fine-needle aspiration (FNA) allows to increase the diagnostic accuracy of EUS in this setting; however, it is technically demanding (a pathologist is also essential) and is furthermore associated with small, but not insignificant morbidity. EUS pancreatic elastography, by analyzing tissue stiffness, arises as a new and very useful tool for the differential diagnosis of solid pancreatic masses. Elastography provides specific patterns supporting the benign or malignant nature of the disease. However, there is a handicap related to the subjective interpretation of images. Second-generation elastography has been recently developed, and allows a quantitative analysis of tissue stiffness. It is based on the determination of a strain ratio (obtained after comparing the strain value of the mass to a strain value from a control area in the region under study). We present two cases reflecting the usefulness of second-generation elastography in the differential diagnosis between pancreatic adenocarcinoma and an inflammatory mass in the context of chronic pancreatitis. We found significant differences between both masses in the strain ratio values (25.46% in the pancreatic adenocarcinoma vs. 2.35% in the inflammatory mass). Second-generation elastography is a very useful tool for the differential diagnosis of solid pancreatic masses.