What Is Pancreatic Cyst?

Overview

Pancreatic cysts are mucus or fluid-filled cysts or lesions that develop in and round the pancreas. Generally, most pancreatic cysts are small and do not require any vigorous treatment apart from regular monitoring and blood tests. However, on rare occasions a pancreatic cyst can become cancerous. Pancreatic cysts are broadly classified as mucinous and nonmucinous cysts based on their ability to produce a substance called mucin found in cyst fluid. Mucinous cysts comprise of a mucin-producing epithelial layer and include intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) while nonmucinous cysts include simple cysts, pseudocysts and serous cystadenomas.¹

• IPMN –  cysts that are normally filled with mucus and generally do not cause any symptoms but can lead to pancreatitis or pancreatic duct blockage. IPMN are further classified on the basis of the duct they occur in and are known as main duct, branch duct and mixed IPMN
• MCNs – large, mucin producing cysts, commonly found in those assigned female at birth (AFAB)  and involve the tail of the pancreas rather than the ducts and have the ability to become cancerous
• Solid pseudopapillary neoplasm – large, well-demarcated, mixed cystic and solid tumours
• Serous cystadenoma – further classified as microcystic type serous cystadenoma and macrocystic serous cystadenoma. Microcystic type serous cystadenoma can be recognised by a honeycomb appearance made up of small cysts arranged around a central stellate (star-shaped) scar with calcification. Macrocystic serous cystadenoma are indistinguishable by X-Ray from other pancreatic lesions. They are mostly non- malignant
• Simple cysts – rarely found in adults, comprising a single epithelial layer, are not involved with the pancreatic ductal system and pose no risk of malignancy (evolving into cancerous tissue)
• pseudocysts (a condition caused as a complication of pancreatitis in which fluid collection occurs around pancreas)

With improved quality of CT and MRI scan, it has become easier to find and visualise pancreatic cysts. ⁵

Causes of pancreatic cysts

The exact cause of pancreatic cysts remains unknown. Quite often, they are diagnosed incidentally during abdominal image scanning (CT or MRI) for some other ailment. However, the incidence of pancreatic cysts is higher in patients with a previous history of pancreatitis and/or those who have a family history of pancreatic cancer. Rarely, they are associated with a rare genetic mutation called von Hippel-Lindau disease that affects the pancreas and leads to cyst development. But the exact mechanism by which the cysts develop and the underlying causes still remain a mystery.¹

Signs and symptoms of pancreatic cysts

Patients generally experience no symptoms. Those who do express symptoms usually experience the following:

• Back pain
• Abdominal pain 
• Weight loss
• Jaundice
• Steatorrhea (increase in fat secretion in stools) 
• A palpable mass (lump) in the abdomen with a bulge or swelling around the area of the lump

Since the symptoms are nonspecific and overlapping with other diseases or conditions, a full patient history is required to differentiate cysts from other conditions. Thus, part of the complete work-up would involve a history of alcohol and smoking intake, NSAIDs use; history of liver, pancreatic, biliary or peptic disease; fever or chills.¹

High risk features – high risk or worrisome features are used to describe clinical and imaging findings that show increased risk of malignancy. High risk features include:

• Obstructive jaundice without an alternate explanation
• New-onset or worsening diabetes
• Recurrent pancreatitis
• Cells demonstrating neoplasia (uncontrolled cell growth) and dysplasia (presence of abnormal cells in tissues or organs)
• More than 5 mm dilated pancreatic duct
• Cyst(s) larger than 3cm in diameter containing a solid component or mural nodule

Patients displaying high risk features are referred to specialists for further work up, management and/ or treatment.⁵ 

Management and treatment for pancreatic cysts

Management and treatment involves periodic check-ups and monitoring, and surgical resection (removing part of the tissue or organ) based on patients’ symptoms, clinical findings, cyst size and presence or absence of high risk features.  Simple cysts and pseudocysts, being asymptomatic and non-cancerous, do not require surveillance. Cysts lacking high-risk features are candidates for surveillance, whereas active surveillance is carried out on cysts such as IPMNs and MCNs that have a tendency to become cancerous and those cysts that display high-risk features. 

Ongoing surveillance is usually carried out, by non-invasive techniques such as MRI and CT scans, and aids early detection and possible curative surgery. There are no specific guidelines as to how long the cysts should be monitored, a topic frequently debated over, however, surveillance is offered to patients as long as they remain surgically fit enough.⁴

The guidelines covering surgery for patients with IPMNs and MCNs differ, however patients demonstrating one or more of the following high risk factors:

• Obstructive jaundice
• Pancreatic duct dilation greater than 10mm 
• Enhancing mural nodule greater than 10 mm

are directed to surgical specialists without further testing. Patients with signs  of cancer or dysplasia in a cyst, who undergo surgical resection, are also advised to undergo surveillance post-surgery. 

It has been observed in a case-study of post-surgical patients with IPMNs and MCNs that IPMNs has a recurring tendency and can lead to both invasive and non-invasive cancer. ⁴

FAQs

Are pancreatic cysts common?

There have been many studies to determine exactly how prevalent pancreatic cysts are. An improvement in imaging techniques have led to more people being diagnosed with them. Studies conducted in Mayo Clinic have shown an increase by 46.1% in the older population over the last decade as well as increased incidental detection with improved MRI hardware. Despite the increasing prevalence or increasing detection, most patients do not experience complications and even fewer of them develop cancer.⁵

Who are at risk of pancreatic cysts?

Pancreatic cysts is an ailment that can strike anyone, regardless of the age. However, patients with a history of pancreatitis (a condition where the pancreas become swollen or inflamed) and those with a family history or previous history of pancreatic cancer have a greater risk of developing pancreatic cysts.  

How are pancreatic cysts diagnosed?

The current work up involves diagnosis by MRI or pancreatic CT. The images are then studied to determine the type of cyst based on the morphology. To differentiate between nonmalignant, premalignant and malignant cysts, an advanced technique known as EUS (endoscopic ultrasound) is used. EUS examination can help determine the size of the cyst, its location, wall thickness, associated mass or mural nodule, and dilation of the pancreatic duct. Combining EUS with fine needle aspiration (EUS-FNA) allows analysis of the cyst fluid to detect the presence of biomarker CEA (carcinoembryonic antigen) whose high-levels indicate the presence of mucinous cysts and indicate that the patient requires surveillance.^3,4,

How can I prevent pancreatic cyst?

The best way to avoid pancreatic cysts is to avoid pancreatitis, which is usually caused by gallstones and/or by drinking excessive alcohol. A balanced diet of fruits, vegetables and wholegrains can help to prevent gallstones, as can maintaining a healthy weight and avoiding fatty foods. Since gallstones are linked with higher cholesterol levels, to avoid them one must exercise often and eat healthily.²

When should I see my doctor?

Individuals should seek medical advice when they experience symptoms such as nausea, bloating and abdominal pain. Pancreatic cysts are often associated with new onset of diabetes, so individuals who experience these symptoms along with diabetes or have a family history related to  pancreatic cancer should get themselves checked.

Summary

Pancreatic cysts are fluid filled lesions that develop in and around pancreas.The older population are generally more susceptible than the younger. Although the exact cause of their occurrence remains a mystery, it has been seen that individuals with a history of pancreatitis or pancreatic cancer are more likely to develop.Quite often, the cysts are not dangerous, but some do carry the potential to become cancerous. Individuals who experience the above mentioned symptoms should seek medical aid. Doctors begin the work-up by taking the full patient history and if pancreatic cysts are indicated, then the individual is advised to go for blood tests and imaging such as MRI. The medical community is still debating over the exact protocol for management and treatment of pancreatic cysts, however the one consensus they stand on is that pancreatic cysts should not be ignored, especially as some carry the ability to become malignant.