Endoscopic ultrasound in the diagnosis, staging, and management of gastrointestinal and adjacent malignancies

Endoscopic ultrasound (EUS) was initially developed in the early 1980s primarily to overcome the limitations of transabdominal ultrasound in imaging the pancreas. In EUS, a small high-frequency ultrasound transducer is incorporated into the tip of a flexible endoscope. EUS is now recognized as the best modality for local staging of esophageal, gastric, and rectal cancer, with T staging accuracy near 90%, and for identification of pancreatic tumors with a sensitivity of over 95% [1-6]. In interventional endosonography, linear array echoendoscopes permit real-time EUS-guided puncture of target lesions for cytologic evaluation of such lesions.