Although large or malignant pancreatic cysts can present with symptoms, the vast majority of pancreatic cysts are incidental lesions discovered on abdominal imaging examinations. Pancreatic cysts occur in up to 25% of patients undergoing abdominal imaging. The increasing resolution of both CT and magnetic resonance imaging (MRI) allows detection of cysts less than 2 cm in size. Although a few of these cysts are premalignant, the majority will remain clinically insignificant; this has created controversy about how these cysts should be evaluated and when they should be surgically resected. Dr Brugge has reviewed the types of cyst pathology and their natural history. By depending on the cyst appearance and its location within the pancreas, he has indicated when a cyst fluid aspirate by EUS-guided FNA (EUS-FNA) is useful and when surgical resection should be entertained. – Grace H. Elta, MD, Editor