Diagnosis and Management of Pancreatic Cysts

We recommend caution when attributing symptoms to a pancreatic cyst. The majority of pancreatic cysts are asymptomatic and the nonspecific nature of symptoms requires clinical discernment.

Magnetic resonance imaging (MRI) or magnetic resonance cholangiopancreatography (MRCP) are the tests of choice because of their non-invasiveness, lack of radiation, and greater accuracy in assessing communication between the main pancreatic duct and the cyst (which is a characteristic of side-branch IPMNs). Pancreatic protocol computed tomography (CT) or endoscopic ultrasound (EUS) are excellent alternatives in patients who are unable to undergo MRI. Indeterminate cysts may benefit from a second imaging modality or cyst fluid analysis via EUS.

Use caution when using imaging to diagnose cyst type or concomitant malignancy; the accuracy of MRI or MRCP in diagnosing cyst type is 40–50% and in determining benign vs. malignant is 55–76%. The accuracy for CT and EUS without FNA is similar.

Patients who are not medically fit for surgery should not undergo further evaluation of incidentally found pancreatic cysts, irrespective of cyst size.

Patients with asymptomatic cysts that are diagnosed as pseudocysts on initial imaging and clinical history, or that have a very low risk of malignant transformation (such as serous cystadenomas) do not require treatment or further evaluation.

EUS-FNA and cyst fluid analysis should be considered in cysts in which the diagnosis is unclear, and where the results are likely to alter management. Analysis of cyst fluid CEA may be considered to differentiate IPMNs and MCNs from other cyst types, but cannot be used to identify IPMNs and MCNs with high-grade dysplasia or pancreatic cancer.

Cyst fluid cytology should be sent to assess for the presence of high-grade dysplasia or pancreatic cancer when the imaging features alone are insufficient to warrant surgery.

Molecular markers may help identify IPMNs and MCNs. Their use may be considered in cases in which the diagnosis is unclear and the results are likely to change management.

Cyst surveillance should be offered to surgically fit candidates with asymptomatic cysts that are presumed to be IPMNs or MCNs.

Patients with IPMNs or MCNs with new-onset or worsening diabetes mellitus, or a rapid increase in cyst size (of >3 mm/year) during surveillance, may have an increased risk of malignancy, so should undergo a short-interval MRI or EUS±FNA.

Patients with IPMNs or MCNs with any of the following features should undergo EUS±FNA and/or be referred to a multidisciplinary group for further evaluation:

1. Any of the following symptoms or signs: jaundice secondary to the cyst, acute pancreatitis secondary to the cyst, significantly elevated serum CA 19-9.

2. Any of the following imaging findings: the presence of a mural nodule or solid component either within the cyst or in the pancreatic parenchyma, dilation of the main pancreatic of >5 mm, a focal dilation of the pancreatic duct concerning for main duct IPMN or an obstructing lesion, mucin-producing cysts measuring ≥3 cm in diameter.

3. The presence of high-grade dysplasia or pancreatic cancer on cytology.

Patients with a solid-pseudopapillary neoplasm should be referred to a multidisciplinary group for consideration of surgical resection.

MRCP is the preferred modality for pancreatic cyst surveillance, given the lack of radiation and improved delineation of the main pancreatic duct. EUS may also be the primary surveillance tool in patients who cannot or choose not to have MRI scans.

In the absence of concerning features (Table 3), which warrant increased surveillance or referral for further evaluation, cyst size guides surveillance intervals for presumed IPMNs and MCNs (Figure 2).

Surveillance should be discontinued if a patient is no longer a surgical candidate.

It is reasonable to assess the utility of ongoing surveillance in those >75 years old. An individualized approach for those 76–85 years should be considered including an informed discussion about surgery.

Patients with a surgically resected serous cystadenoma, pseudocyst, or other benign cysts do not require any follow-up after resection.

Resected MCNs without pancreatic cancer do not require postoperative surveillance.

All surgically resected IPMN require postoperative surveillance.

Patients should be followed on a yearly basis for at least 5 years following resection of a solid-pseudopapillary neoplasm.