The ever-increasing use of radiographic imaging of the abdomen, in particular by CT and MRI, has led to a significant rise in the discovery of patients with pancreatic cysts. Often these are coincident findings, and not the cause of the signs or symptoms that may have initially led to these patients being referred for such imaging. Accordingly, providers are left with several questions about how they should approach further diagnostic or surveillance strategies in these patients.
Over the past few years, guidelines on this topic have been published by the American Gastroenterological Association, the American College of Gastroenterology, the American College of Radiology, and the European Study Group on Cystic Tumours of the Pancreas. These guidelines have differed in their consistency due to lack of high-quality evidence.
Thankfully, a recent review article has collected this information in one place to provide practical strategies for management and surveillance.
Here are my top 13 highlights and key takeaway messages from that review.
A main through-line in the various guidelines is the importance of determining the type of cyst and risks for neoplasia.
There is no risk for progression with pseudocyst or serous cystadenomas, while in contrast, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms (IPMNs) have premalignant potential for subsequent progression to cancer. Solid tumors of the pancreas may undergo cystic degeneration, and hence, have both solid and cystic components.
Patients with a pseudocyst typically have a history of pancreatitis.
Cyst fluid would have high amylase and low (< 5 ng/mL) carcinoembryonic antigen (CEA) levels.
Serous cystadenomas are typically a single cyst or multiple small cysts, without communication to the main pancreatic duct.
CEA levels are low after cyst fluid analysis.
Evidence of the von Hippel-Lindau tumor suppressor gene confirms its diagnosis with a sensitivity of 46% and a specificity of 100%.
Mucinous cystic neoplasms typically occur only in women, in the body or tail of the pancreas. These are single cysts without pancreatic duct communication.
Mucinous cystic neoplasms and IPMNs may have mutations of KRAS (both mucinous cystic neoplasms and IPMNs) or GNAS (IPMNs only).
MRI is the preferred radiologic test in accurately evaluating communication between a cyst and the main pancreatic duct.
Endoscopic ultrasound is more invasive but is the most sensitive test for cytology and fluid analysis. However, it's typically reserved for when findings are likely to alter the management strategies.
High-risk features of IPMNs include jaundice due to cyst-related biliary compression, pancreatic duct of ≥ 10 mm, mural nodule of 5 mm or solid mass, and/or cytology with high-grade dysplasia or cancer.
Worrisome features for pancreatic neoplasia include acute pancreatitis, mural nodule of < 5 mm, main pancreatic duct size of 5-9 mm, abrupt pancreatic duct caliber changes, increased serum level of CA 19-9, cyst > 3 cm, or rapid increases in size (2.5-5 mm/year).
The development of new-onset diabetes should warrant repeat imaging and shortened surveillance intervals.
Patients with evidence of high-risk or worrisome features should be evaluated via endoscopic ultrasound with fine-needle aspiration.
Surgical referral should be done for cysts > 3 cm. Resection is typically performed only for lesions > 4 cm or those with other high-risk or worrisome features.
No surveillance is recommended following resection (if done) for pseudocysts, serous cystadenomas, or mucinous cystic neoplasms.
However, surveillance is recommended for patients with IPMN and a remnant pancreas. Most recommendations are for every 2 months for 2 years, then annually if high-grade dysplasia is evident.
While surveillance can be stopped if patients are older than 75 years, the risks and benefits should be assessed and discussed with them.
Stopping surveillance is also advised if there are no changes in the cyst size for at least 5 years; the guidelines range from 5 to 10 years in this regard.
There are potential harms for invasive evaluation and significant costs related to the treatments for pancreatic cysts. Efforts should be made to appropriately evaluate and minimize unnecessary surveillance and resections.
David A. Johnson, MD, a regular contributor to Medscape, is professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia, and a past president of the American College of Gastroenterology. His primary focus is the clinical practice of gastroenterology. He has published extensively in the internal medicine/gastroenterology literature, with principal research interests in esophageal and colon disease, and more recently in sleep and microbiome effects on gastrointestinal health and disease.
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Cite this: David A. Johnson. 13 Tips for Pancreatic Cyst Surveillance - Medscape - Jul 20, 2022.