Diagnosis and fine needle aspiration of pancreatic pseudocysts: the role of endoscopic ultrasound.

Pseudocysts are localized collections of pancreatic fluid surrounded by nonepithelialized granulation tissue that occur following an insult to the pancreas. High image resolution and the ability sample in real-time by fine needle aspiration permit accurate distinction between various cystic lesions in the pancreas by endoscopic ultrasound (EUS). Other cyst characteristics and background pancreatic changes detectable at EUS assist in the diagnostic process. The use of Doppler flow ultrasound allows diagnosis of important pseudocyst complications such as pseudoaneurysms and varices. Endoscopic approaches to the drainage of symptomatic lesions previously relied on the use of cross-sectional imaging studies such as computed tomography scanning in combination with stent placement using a duodenoscope in the presence of an endoscopically visible cyst bulge. EUS facilitates this process allowing accurate imaging of the lesion prior to stent placement via the echoendoscope and overcomes many of the drawbacks and pitfalls of other endoscopic techniques.