Molecular analysis of cyst fluid aspiration in the diagnosis and risk assessment of cystic lesions of the pancreas.

Pancreatic cyst detection is increasing largely due to increasing use of cross-sectional imaging. The management of pancreatic cysts differs for true cysts, pseudocysts, mucinous cysts, nonmucinous cysts, and malignant lesions. Depending on the setting, diagnostic tests, such as cross-sectional imaging, endoscopic ultrasound, cyst fluid chemistry, and cytology, have moderate accuracy in characterizing the cyst subtype. Molecular analysis of cyst fluid aspirates has shown promise in preliminary studies and may require smaller fluid volumes than is needed for carcinoembryonic antigen level and cytology. This article reviews published studies in which molecular analysis was performed in the evaluation of pancreatic cysts. The molecular studies are compared with the conventional tests. Most studies have had moderate sample sizes (16-124) and have characterized a high proportion of patients with malignant cysts. Evaluation of molecular analysis as a diagnostic tool merits larger prospective trials with long-term follow-up of patients who are not sent to surgery. Larger cysts may meet size criteria for resection, and it is the smaller cysts for which molecular analysis may be of benefit if additional molecular testing results in a change in management.