Current status of diagnostic endoscopic ultrasonography in the evaluation of pancreatic mass lesions.

Endoscopic ultrasonography (EUS) is currently well established as a diagnostic method for the evaluation of pancreatic mass lesions. Diagnostic EUS might be divided into two broad categories; it is an imaging method, and also a device for obtaining cytopathology and histopathology. EUS as an imaging method has seen the introduction of newer intravenous contrast agents that enable the characterization of the pancreatic masses. EUS elastography enables real-time graphical representation of differential tissue hardness within a lesion. Contrast-enhanced EUS and/or elastography provide information additional to the fundamental images, leading to more accurate diagnosis. EUS-guided fine needle aspiration (EUS-FNA) has been shown to be a highly accurate method for distinguishing benign from malignant pancreatic masses. Several investigators have reported the usefulness of EUS-FNA samples obtained from pancreatic masses for genetic analysis, e.g. p53, K-ras. Genetic analysis of EUS-FNA samples to characterize chemo-sensitivity has recently been attempted in patients with unresectable pancreatic cancers. Although further improvement of EUS technology is desired to render it an even more convenient and reliable procedure, EUS at its current level of advancement is of proven utility in the diagnosis of pancreatic masses.