Pancreatic cysts are fluid-filled sacs on or in the pancreas. There are different types of pancreatic cysts which vary in their potential for malignancy and the type of treatment needed. Typically, benign cysts include pseudocysts and serous cystadenomas. Potentially malignant cysts include intraductal papillary mucinous neoplasms and mucinous cystadenomas. Other abnormalities, such as neuroendocrine neoplasms, may look like cysts and need to be correctly identified before a diagnosis can be made. Most pancreatic cysts are benign.
No data are available for the UK, but the reported prevalence of pancreatic cysts in the general population (derived from studies done in the US, Japan, Holland and Ireland) varies from 1.2% to 24.3% (de Jong et al. 2012). Most pancreatic cysts do not cause symptoms and are detected by chance when people have abdominal MRI or CT scans. According to the American Gastroenterological Association, unsuspected pancreatic cysts are found in about 15% of patients having an abdominal MRI for other indications (Vege et al. 2015).
Endoscopic ultrasound with fine needle aspiration (EUS‑FNA) is the standard procedure used to characterise pancreatic cysts. In the procedure, the person is sedated and an endoscope with an ultrasound probe is passed through the mouth and stomach into the duodenum. Ultrasound waves are used to identify abnormalities within the pancreas. If an abnormal area is detected, a very fine needle can be passed into it to take a sample of tissue or fluid. EUS‑FNA alone may not be accurate enough to characterise all pancreatic cysts and the analysis of cyst fluid does not consistently allow specific cyst types to be identified or predict malignancy potential. An inconclusive EUS‑FNA typically results in a follow‑up EUS‑FNA or CT‑guided FNA procedure, with surgery being considered for some people if there is concern about the nature of the lesion. Providing a more accurate diagnosis during the EUS‑FNA procedure would inform more appropriate management, including options for surgery and surveillance intervals. Needle-based confocal laser endomicroscopy (nCLE) generates 'optical biopsies', providing endoscopists with real-time microscopic images of tissues to use in addition to or in place of information obtained by standard biopsies. This could potentially allow for a quicker, more accurate diagnosis of benign and malignant cysts.