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.Key words: Endoscopic ultrasound. Elastography. Second-generation Elastography. Pancreatic tumors.
INTRODUCTIONEndoscopic ultrasonography (EUS) has become a basic tool for the study of pancreatic diseases, and is considered one of the most accurate methods for the diagnosis and staging of both chronic inflammatory and neoplastic pancreatic diseases (1,2). However, differentiation between pancreatic cancer and focal pancreatitis remains a challenge. EUS can guide fine-needle aspiration (EUS-FNA) for the collection of cytological samples from pancreatic lesions with a very high overall diagnostic accuracy (3-7). EUS-FNA may be, however, technically demanding, and multiple puncturing of pancreatic lesions may be needed to obtain adequate material for cytological or microhistological evaluation. EUS-FNA of the pancreas, despite being considered very safe, is furthermore associated with a small, but not insignificant morbidity (8,9).Elastography is a method for the real-time evaluation of tissue stiffness, which has been used for the analysis of superficial organ lesions such as those of the breast (10-13). Images obtained by elastography represent tissue elasticity, which may reflect histopathological differences (14). The association of this technology with EUS has implied a significant advance in the management of pancreatic diseases, mainly in the differential diagnosis of pancreatic tumors (15). A new advance has been recently developed -secondgeneration elastography. This technique allows not only a qualitative elastographic analysis, but also a...