Long-term follow-up of patients with incidentally discovered pancreatic cystic neoplasms evaluated by endoscopic ultrasound

Background: The management of incidental pancreatic cysts is not well established because of lack of information on their natural history. International Consensus Guidelines advocate observation of asymptomatic patients with small lesions, despite limited data to support this approach. Methods: To characterize clinical outcomes in a cohort of asymptomatic patients with incidental pancreatic cysts who underwent endoscopic ultrasound (EUS) evaluation ± fine needle aspiration (FNA). Results: Overall, 317 patients underwent EUS for evaluation of pancreatic cysts from 1995 to 2005. A total of 97/317 (31%) had asymptomatic, incidentally discovered pancreatic cysts; of 97 asymptomatic patients, 93 were contacted. Of these patients, 71/93 (76%) had lesions<3 cm and benign EUS features. All were followed without operative therapy. The mean follow-up was 44 months (range, 6-123). A total of 69/71 (97%) were alive and free of symptoms of pancreatic disease; 2 patients died of unrelated causes. Among these 71 patients with lesions <3 cm, FNA was performed in 33 patients and cytology was negative for malignant cells in all. Overall, 45/71 patients had either follow-up cross-sectional imaging or EUS. All of them had stable lesions. Surveillance studies were performed with a mean follow-up of 28 months (range, 4-120). The 22 patients with lesions >3 cm and/or concerning EUS features underwent resection. Pathologic analysis revealed that 2/22 patients had adenocarcinoma and that 60% had premalignant lesions. Conclusion: Endoscopic ultrasound is helpful in evaluation of patients with small incidental pancreatic cystic lesions. Asymptomatic cysts with benign radiographic and/or endosonographic features may safely be followed clinically and with serial imaging.