What You Should Know About the IPMN Tumor

Intraductal papillary mucinous neoplasm (IPMN) is a type of cyst that is found in the pancreas. These cysts are benign - meaning they are not cancerous to start. However, they are concerning because in a minority of cases an IPMN can develop into malignant (cancerous) tumors. These cancerous tumors become invasive and are a form of pancreatic cancer that is difficult to treat. 

Being diagnosed with an IPMN can be confusing and upsetting, especially when looking for information on the potential for cancer and in understanding what is next for monitoring and treatment options. In many cases, an IPMN is found on a test that’s being done for something unrelated to the pancreas. During this time it’s important to seek out opinions from one or more specialists to find out what all the options are.

Keeping good records and getting information from other physicians about past health problems (and especially anything to do with the pancreas, like pancreatitis), is also helpful in decision-making. Finally, acknowledging and talking with loved ones and with healthcare providers about the stress and uncertainty may also help.

The Pancreas

The pancreas is an organ in the abdomen that sits behind the stomach. The pancreas has a main duct that contains many branches. The pancreatic duct connects to the first part of the small intestine (called the duodenum). The digestive enzymes produced in the pancreas travel through the branches, into the main duct, and then into the duodenum.

It’s often forgotten, but the pancreas produces vital hormones and plays a key role in the digestive and metabolic processes. The pancreas produces insulin, which is a hormone that plays a few roles in the body’s metabolism, including helping the absorption of glucose (sugar) by the body’s muscles, fat, and liver. Without enough insulin produced by the pancreas, the body’s blood sugar can rise. Consistently high blood sugar can lead to the body’s cells not getting enough energy as well as to the development of many different health conditions. Diabetes is a disease associated with high blood sugar, and some forms are caused by the pancreas either not producing enough insulin or not using insulin effectively. 

The pancreas also produces glucagon, which is a hormone that raises the glucose level in the blood. Glucagon will help prevent blood sugar from becoming too low (called hypoglycemia). Together with insulin, glucagon helps regulate blood sugar and keep it at an even level in the body. It’s rare for the pancreas to produce too much or too little glucagon. Having an IPMN, however, can contribute to a lowered production of glucagon.

Pancreatic Cysts

Researchers at Johns Hopkins ran a study to find out how many people had IPMNs that were not causing any symptoms. They looked at the computerized tomography (CT) scans of 2,832 patients which included the pancreas. What they discovered was that even though none of the patients had any pancreatic symptoms, 2.6 percent of them had a pancreatic cyst. 

A cyst is a group of cells that forms a sac, which could be filled with fluid, air, or solid material. There are a few different types of cysts that can form in the pancreas, with the two main ones being serous and mucinous. An IPMN is a mucinous cyst, and one of the characteristics is that they contain fluids that are more viscous than those found in serous cysts. Further study showed that the majority of the cysts found in the Johns Hopkins research were IPMNs.

IPMNs form inside the ducts of the pancreas. They are different from other types of cysts because they have projections that extend into the pancreatic duct system. 

Studies show that pancreatic cysts are more common as we age. In the Johns Hopkins study, no patients under the age of 40 years had a cyst and the percentage of cysts in the 80 to 89-year-old age group jumped to 8.7 percent.

Signs and Symptoms

In most cases, people don’t know that they have an IPMN and there aren’t any symptoms. Sometimes an IPMN is found during imaging tests that are being done to look for another problem or condition and happen to include the pancreas. In some cases, people with an IPMN may develop acute pancreatitis, which prompts them to seek treatment. Some of the first signs and symptoms patients may experience are non-specific (meaning they could be caused by a variety of conditions) and include:

• Abdominal pain
• Jaundice
• Nausea
• Unintended weight loss
• Vomiting

Diagnosis

There are several tests that might be used to look for an IPMN or to monitor one once it's discovered.

CT scan

A CT scan is a specialized X-ray that might be done with the use of contrast dye. It is non-invasive and is done by the patient lying on a table that slides partway into the CT machine so that images can be taken of the abdomen. The machine takes images while the patient lies still, sometimes being asked to hold their breath. This test can help in visualizing the pancreas and in looking for or confirming the presence of an IPMN.

Endoscopic Ultrasound (EUS)

An EUS uses sound waves to see the organ and structures in the abdomen, such as the stomach, small intestine, pancreas, bile ducts, and liver. Patients are given sedatives during an EUS, and it tends to take between a half an hour and an hour to complete. During the test, a thin tube is passed through the mouth and stomach and into the small intestine. The images from this test may help show if there are any abnormalities in the pancreas.

In some cases, a biopsy might be done because the locations of the organs are seen on the images, and this assists a physician in guiding a needle into the abdomen and to the right spot for taking the biopsy. This test might be done after an IPMN or a suspected IPMN is found during another test.

Magnetic Resonance Cholangiopancreatography (MRCP)

An MRCP is a non-invasive test that uses a strong magnetic field to view the liver, pancreas, gallbladder, and bile ducts. This test can show if the bile ducts are obstructed, such as by a suspected IPMN.

Contrast dye, given either via a drink or an IV, may be used during this test to help enhance the images. Patients lie on a table that slides into the center of the machine. During the test, patients are asked to hold still. The test can take about 45 minutes or so to complete.

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Types of IPMNs

Based on studies of surgically removed IPMNs, the cysts are usually put into one of two categories by pathologists (a physician that specializes in the study of tissues, organs, and bodily fluids).

The first category is where there is no invasive cancer and the second is when there is invasive cancer associated with the IPMN. A major difference between the two types is in the prognosis because patients with IPMNs that are not associated with invasive cancer have a five-year survival rate that’s been reported as being between 95% and 100%.

IPMNs are further classified based on where in the pancreas they are located: in the main duct or in the branches off the main duct, or in both places (mixed). There is some evidence that branch duct IPMNs are less likely to have an associated invasive cancer than main duct IPMNs. However, the authors of other research papers indicate that there is not such a clear difference between the two because either type could be associated with cancer.

The size of the IPMN also appears to be important, with larger ones (greater than 30 millimeters) being more concerning than smaller ones. The importance of classifying and understanding IPMN types comes into play when making decisions on treating them with surgery or monitoring them to see if they change/grow over time.

IPMNs that are present without invasive cancer might also be put into one of three subtypes: low-grade dysplasia, moderate dysplasia, and high-grade dysplasia. Dysplasia refers to an abnormal state in a cell. In some cases cells that means that the cell is pre-cancerous. With IPMNs, it is thought that they change over time from low-grade dysplasia to high-grade dysplasia. It’s believed that an IPMN may then have a chance of progressing to invasive cancer.

For those with IPMNs that are associated with invasive cancer, the prognosis varies widely based on a number of factors. One of these factors is the subtype of IPMN found, with the two forms being colloid carcinoma and tubular carcinoma. The estimated five-year survival rate for colloid carcinoma ranges from 57 to 83 percent, and from 24 to 55 percent for tubular carcinoma.

Treatment

In most cases, an IPMN is not considered to be at a high risk of developing into cancer, and so watchful waiting is all that is done. Tests that monitor the size of the IPMN, such as those described above, are done at regular intervals. Small IPMNs in a branch might be monitored yearly but larger ones could need an evaluation as often as every three months.

If or when there are any changes, such as the IPMN growing larger, decisions can be made about treatment. The risk of treatment needs to be carefully weighed against the probability of cancer. For people who have symptoms associated with the IPMN, even if it is considered to be a low risk for cancer, treatment might be needed. 

IPMNs that are found in the main duct may be considered for surgery more often than those found only in the branches. Therefore, if a patient is well enough to undergo surgery, it’s usually recommended that these IPMNs are removed. This may mean that part of the pancreas is surgically removed.

This is major surgery and may be done openly, which includes making an incision on the abdomen. In some cases, surgery might be done laparoscopically. This means that minimally invasive techniques are employed, which includes making only small incisions and using a tiny camera to complete the surgery. It’s usually recommended that surgeries to remove all or part of the pancreas be done by a surgeon who has a lot of experience with these procedures.

Distal Pancreatectomy

This is a procedure to remove a section from the body and the “tail” of the pancreas, which is the part of the pancreas that is closest to the spleen. In some cases, the spleen may also be removed. Most people will have enough of their pancreas left after surgery that the production of hormones and enzymes is not affected. If more pancreas must be taken, it could be necessary to supplement with medications or enzymes that are no longer being produced by the body in sufficient amounts. 

Pancreaticoduodenectomy

This surgery, which is also called the Whipple procedure, is done when the IPMN is in the distal, or “head" of the pancreas. During this surgery, the head of the pancreas is removed. In some cases, the duodenum, part of the bile duct, the gallbladder, and part of the stomach are also removed. In this scenario, the stomach will be connected to the second part of the small intestine (the jejunum).

Total Pancreatectomy

This surgery is rarely used to treat IPMNs, and may only be needed if the IPMN extends through the entire main duct. This is the removal of the entire pancreas, as well as the spleen, the gallbladder, the first part of the small intestine, and part of the stomach. The stomach will then be connected to the second section of the small intestine (the jejunum) in order to preserve digestion.

After this surgery it will be necessary to work with a specialist, called an endocrinologist, to replace the hormones and enzymes in the body that are normally made by the pancreas. Most notably, medications will be needed to regulate blood sugar, because both glucagon and insulin are no longer being made by the body. 

A Word From Verywell

The idea of having an IPMN, especially when it’s found accidentally, can be really concerning. However, in most cases, these cysts don’t cause any symptoms and most people don’t know they have them. They can usually be monitored for any changes and no treatment is needed. A minority of cases might need surgery to remove them, but this is in order to lower the risk of developing associated cancer.

Most people will recover well from treatment. If more invasive cancer is found, there could, unfortunately, be a need for more radical surgery. Research into IPMN has led to a greater understanding of how to manage and treat them, and surgical techniques have improved greatly. The outlook for those that have a symptomatic or complicated IPMN is brighter now than it has ever been.