Endoscopic Ultrasound for Solid and Cystic Neoplasms of the Pancreas

Endoscopic ultrasound (EUS) was introduced in clinical practice in 19801 and during the last few decades the quality of instrumentation has improved significantly. The first commercially available radial echoendoscope was introduced in Japan 2 and then in Europe 3 in the mid to late 1980s. At that time, radial probes were used for fine needle aspiration (FNA). Only in the early 1990s EUS-FNA become technologically practical with the introduction of linear echoendoscopes that generated ultrasonic images parallel to the shaft of the instrument. With this modification, needles could be guided into areas of interest. Soon after this improvement, the first report of EUS-FNA of the pancreas was published 4 and numerous other publications have followed 5-8. Later on, mechanical probes have been replaced by electrical probes that allowed expansion of the diagnostic capacity of EUS. More recently, the addition of color Doppler ultrasonography, injection of contrasts for ultrasound and the application of elastography has further extended the clinical use of EUS for hepatobiliary and pancreatic diseases. The fact that EUS is able to provide direct visualization of the walls of the gastrointestinal tract and direct the placement of needles for cytology or histology specimens 5,9, makes this technique very useful for the diagnosis of benign and malignant diseases of these organs that are difficult to reach percutaneouly. In recent years diagnostic modalities such as multidetector-multiphasic CT with pancreatic protocols, magenetic resonance imaging (MRI) and positron emission tomography (PET) scans have improved significantly the pre-operative tumor staging of pancreatic malignancies. Nevertheless, a significant proportion of patients will benefit from EUS-FNA for confirmation of pancreatic neoplasm and assessment of the planes along the vascular superior mesenteric trunk10.