Intraductal Papillary Mucinous Neoplasm
Pancreas gland produces digestive juices, which it delivers to the small intestine via a hollow branching tube called the pancreas duct. The duct system consists of the main pancreas duct and branch ducts. Occasionally, a part of the lining of the pancreas duct becomes abnormal, grows finger-like projections and secretes mucus. This mucus is too thick to drain out through the narrow ducts causing plugging and ballooning of the ducts. This condition of cyst-like enlargement of the ducts(s) is called intraductal papillary mucinous neoplasm (IPMN), a benign but precancerous (has the potential to transform from a benign cyst to a malignant tumor) cyst of the pancreas.
IPMNs that involve the main pancreatic duct are called main duct type IPMNs while the cysts that arise in one of the branches of the main duct are called branch duct type IPMNs. When both the main duct and side branch ducts are involved, the tumor is called mixed type IPMN. Mixed type IPMNs are treated like main duct IPMNs are the most worrisome types of IPMNs as they have the highest risk of cancer.
Main duct IPMN
Once a main duct type IPMN is identified, the next most important step is to determine if that individual is a suitable surgical candidate. Approximately 70% of these cystic tumors are either cancerous or harbor high-grade dysplasia (one step before invasive cancer develops) at time of diagnosis. For this reason, surgery is recommended if the patient is a good surgical candidate.
Branch duct IPMN
On the other hand most branch duct IPMNs have a much smaller risk of progression to cancer, with approximate risk of progression of 5% or less over a 5 year interval. With most small branch duct type IPMNs, surgical risk may outweigh the benefits of removing the tumor. If the decision is made to observe, rather than remove the branch duct type IPMN, it should be evaluated periodically typically with either MRI/MRCP or endoscopic ultrasound examination depending on cyst characteristics. Timing of interval surveillance (ie, 3 months, 6 months, 1 year, 2 years, or 3 years) depends on several factors such as interval growth of the cyst over time, cyst size, etc. The goal of surveillance is to identify high-risk changes in the cyst over time, should they develop, so that subsequent surgical resection can prevent the development of pancreatic cancer which has a poor prognosis once present.
Symptoms of advanced IPMN can include abdominal pain, jaundice (yellowing of the skin and whites of the eyes), nausea and vomiting, weight loss, and changes in bowel habits. However, the vast majority of people with IPMN do not have any symptoms as the vast majority of them are benign.
Pancreatic cysts are typically incidental findings in which they are found on an imaging test (Ultrasound, CT, or MRI) evaluating something else. Approximately 20% of patients over the age of 70 will have a pancreatic cyst found on imaging. IPMN is usually diagnosed with a combination of imaging tests, such as CT scan or MRI, and a procedure called endoscopic ultrasound (EUS). EUS involves inserting a thin tube with an ultrasound probe into the digestive tract to get a close-up view of the pancreas.
Treatment for IPMN depends on the size and location of the cyst, as well as the presence of any cancerous cells. If a branch duct IPMN is considered high-risk or if a main or mixed-type IPMN is diagnosed, then surgery is often necessary to remove the cyst or affected part of the pancreas. In some cases, chemotherapy or radiation therapy may also be recommended if pancreatic cancer is found in the surgical specimen.
There is no known way to prevent the development of IPMN. Most IPMNs are detected incidentally while looking for other problems. Once detected, getting regular follow up evaluation and surveillance tests of the cysts can help identify cancerous change early, which can improve the chances of a successful treatment.
There is no clear evidence to suggest that IPMN is hereditary. However, some research has indicated that certain genetic factors may increase the risk of developing the condition.
The long-term outlook and prognosis for people with IPMN depends on the size and location of the cyst, as well as the presence of cancerous cells. If the cyst is small and does not contain cancerous cells, the prognosis is generally good. However, if the cyst is large or contains cancerous cells, the prognosis may be more serious.
If the cyst is small and does not contain cancerous cells, it may be possible to cure IPMN with surgery. However, the risk of surgery often outweighs the benefit in this specific situation. If a cyst is considered high-risk but does not contain cancerous cells then a cure can be achieved with surgery; however, if it contains cancerous cells, the chances of a cure may be lower. In these cases, treatment may be aimed at controlling the growth of cancerous cells.
In some cases, medications may be used to treat symptoms related to IPMN. For example, pancreatic enzyme supplements may be prescribed to help with digestion if the pancreas is not functioning properly. However, there are no medications to decrease the likelihood of cyst progression to cancer.
It is generally recommended that people with IPMN maintain a healthy diet and exercise regularly to help manage the condition. However, specific lifestyle changes will depend on the individual’s specific situation and should be discussed with a healthcare provider.
It is possible for IPMN to recur after treatment, even if the cyst is benign. IPMNs are often multifocal and new IPMNs can develop in non-resected areas of pancreas over time. Regular check-ups and surveillance tests can help detect any recurrence early, which may improve the chances of successful treatment.
There is no evidence to suggest that IPMN is more common in men or women. The condition can affect people of any gender. Cysts are more common in older individuals.
It is rare for children to develop IPMN. The condition is more commonly diagnosed in people over the age of 50.
IPMN is usually detected incidentally by imaging tests such as CT scan or MRI which may be ordered for other conditions. However, it is also possible for IPMN to be identified because of development of symptoms such as jaundice or weight loss.