Your pancreas is an organ that sits behind your stomach and helps with digestion by producing enzymes and hormones, including insulin.

Sometimes your pancreas can develop cysts. There are many types of pancreatic cysts, one of which is called a mucinous cystic neoplasm (MCN).

You can develop MCNs in other parts of your body, such as your liver, but in this article, MCNs will refer to those in your pancreas.

Read on to learn more about pancreatic MCNs, what causes them, and how they’re diagnosed and treated.

To better understand what mucinous cystic neoplasms (MCNs) are, it’s helpful to break down the meaning of the words:

  • Mucinous: means made of mucin, which is the main component in mucus
  • Cystic: means cyst-like, which is an abnormal sac that can develop in your tissues
  • Neoplasm: serves as another word for tumor

So pancreatic MCNs are fluid-filled sacs in your pancreas.

MCNs are found almost exclusively in females between the ages of 40 and 60, with a prevalence rate of about 2.6%. Female cases outnumber male cases 20 to 1.

MCNs can be cancerous or precancerous (high-grade dysplasia), but this is only the case about 10% of the time.

Pancreatic cysts

While more research is needed, experts estimate between 11% and 18% of pancreatic cysts are MCNs. Other types include:

  • Intraductal papillary mucinous neoplasms (IPMNs): IPMNs are the most common pancreatic cysts and occur in the ducts that connect your pancreas to your other organs.
  • Serous cystadenomas (SCAs): These represent between 13% and 23% of pancreatic cysts. Most (but not all) SCAs are asymptomatic and don’t require surveillance.
  • Cystic pancreatic neuroendocrine tumors: These make up between 4% and 7% of pancreatic cysts. They occur equally in males and females, usually ages 60 and above.
  • Solid pseudopapillary neoplasms (SPNs): SPNs account for 2% of pancreatic cysts, most commonly in females in their 20s. The 5-year survival rate for SPNs is over 98%.
  • Pseudocysts: These usually only follow a pancreas injury or pancreatitis.

The exact causes of MCNs are unknown, but experts believe they may be related to hormones.

It’s been noted that pancreatic MCNs have a lot in common with ovarian MCNs, including receptors for estrogen, a female sex hormone. This provides some evidence for a hormonal cause.

Pancreatic MCNs are most common in females between the ages of 40 and 60, making this the highest risk group.

Pancreatic MCNs often don’t cause any symptoms.

If an MCN does cause symptoms, these are likely to include:

Doctors use CT scans or MRIs to diagnose pancreatic cysts. You won’t know if your pancreatic cyst is an MCN or another type until after a doctor or medical professional has reviewed these medical scans.

If you don’t have any symptoms, your MCN is usually discovered because you’re having an abdominal exam for another reason.

Medical scans, such as a CT or MRI, are most often used to determine which type of pancreatic cysts you have. You can also expect to have a doctor perform a physical examination.

You might also need laboratory tests to help gather more information about your cysts. These may include a complete blood count or a comprehensive metabolic panel.

In rare cases, you might also need to have a biopsy. Experts suggest a biopsy procedure called an endoscopic ultrasound using fine needle aspiration.

Treatment for your pancreatic MCN will depend on your overall health as well as your MCN’s size and growth rate. Some benign MCNs can become malignant over time. Because there’s no way to tell if a benign MCN will stay benign or not, it’s often best to have it removed.

If a doctor believes you can safely undergo surgery, you’ll likely have the MCN surgically removed. This surgery is called a resection. The risks associated with the surgery are generally low.

If you’re not a good candidate for surgery and if your MCN is smaller than 3 centimeters (cm), you can expect to have regular medical imaging done to monitor your MCN’s progression.

Your pancreas is divided into four regions. These are called the:

  • head
  • neck
  • body
  • tail

About 93% of pancreatic MCNs are found in the body or tail of your pancreas. MCNs in these regions are less likely to be cancerous than MCNs found in your pancreas’ head or neck regions.

Smaller MCNs are less likely to be cancerous. Pancreatic MCNs smaller than 4 cm were only associated with invasive adenocarcinoma in 0.03% of cases.

While females have a much higher risk of developing MCNs, males have a greater chance of their MCNs being cancerous or precancerous. One study found that MCNs in males were malignant or precancerous 39% of the time, while this was just 12% for females.

The 5-year survival rate for benign MCNs is nearly 100%, while for malignant MCNs it’s 57%.

What causes pancreatic cysts to grow?

The exact cause is unknown, but your risk of developing pancreatic cysts could increase if you have a history of pancreatic cancer or pancreatitis.

Can MCNs cause pancreatitis or other disorders of the pancreas?

It’s uncommon, but MCNs can cause recurrent pancreatitis. If left untreated, MCNs can sometimes lead to cancer.

Can MCNs spread to other organs?

Most MCNs are benign and don’t spread to other organs. However, malignant MCNs can spread to other organs and lymph nodes. Experts believe this is more common in older adults.

Is there anything you can do to prevent MCNs from developing?

It’s not known whether you can prevent MCNs specifically, but you can lower your risk of some pancreatic cysts by consuming less alcohol and following a low fat diet.

Pancreatic MCNs are fluid-filled sacs that can develop in your pancreas.

They might not cause any symptoms and are often found when you’re having your abdomen examined for other reasons. Pancreatic MCNs are much more common in females, especially between the ages of 40 and 60.

MCNs can be benign or malignant. Benign MCNs can become malignant over time. For this reason, the most common treatment is to have the MCNs removed in a procedure called a surgical resection.

If you have a history of pancreatitis or pancreatic cancer, or if you’re feeling symptoms that might be caused by MCNs, talk with a doctor about your concerns. They can help you determine the safest way to monitor your pancreas and minimize your risk of cysts.