IPMN Of The Pancreas (Intraductal Papillary Mucinous Neoplasm)

Intraductal papillary mucinous tumor or IPMN is a cystic tumor that arises from the pancreatic duct.  The pancreatic duct runs through the pancreas and carries digestive juices to the intestine.  IPMN is often found on imaging tests like ultrasound, CT and MRI.

IPMN can occur within the main pancreatic duct or its side branches.  IPMN can be a malignant tumor in some cases, particularly when it involves the main duct of the pancreas.  Follow up and treatment is dependent on imaging features.  There are published criteria for followup and treatment (Fukuoka consensus guidelines).

What is IPMN of the pancreas?

Intraductal papillary mucinous neoplasm of the pancreas is a tumor of the pancreatic duct which produces mucin.  These tumors arise most commonly in patients over 50 years old.

Symptoms of IPMN

Many tumors are asymptomatic and found incidentally on imaging studies.  Other tumors can be associated with abdominal pain, weight loss, jaundice and new onset diabetes.

Types of IPMN

Side Branch IPMN

A side branch IPMN is more common and arises from one of the side branches of the pancreatic duct.

Main Duct IPMN

Main duct IPMN can involve the entire duct or a segment of the main duct.

How is IPMN diagnosed?

IPMN is often found on imaging studies like ultrasound, CT, and MRI.  Further testing may be performed with an invasive endoscopic ultrasound.  This allows a close look at the tumor and sampling of its contents.

What does IPMN look like on MRI?

A side branch IPMN will look like a cystic tumor that communicates with the pancreatic duct.

A main duct IPMN will look like a dilated main pancreatic duct.

There can also be tumors which are mixed type and have features of side branch and main duct IPMN.

Worrisome features of these tumors include: solid nodules, thick enhancing wall, dilation of the main pancreatic duct or bile duct, patient having jaundice, tumor size greater than 3 cm, enlarged lymph nodes, atrophy of pancreas distal to the tumor, cyst growth and elevated tumor markers.

What else can look like IPMN in radiology?

Chronic pancreatitis which is an inflammation and scarring of the pancreas can result in a dilated main pancreatic duct.  This can mimic a main duct IPMN.

other cystic tumors of the pancreas like serous and mucinous cystadenoma can mimic IPMN but do not communicate with the pancreatic duct.

What causes IPMN?

It is not clear but there is a change in the DNA of the duct which causes the tumor to grow.

Is IPMN cancerous?

It can be.  IPMN which involves the main pancreatic duct is more likely to be cancerous than the side branch variety.

What type of doctor treats IPMN?

IPMN tumors are often managed by hepatobiliary gastroenterology specialists and surgeons.

IPMN treatment

Resection is recommended for main duct IPMN.  Side branch IPMN is often followed with imaging.  Those side branch IPMNs which have high risk clinical or imaging features are resected.

IPMN: summary

IPMN is a tumor of the pancreatic duct.  It can arise from the main pancreatic duct or a branch.  It is often diagnosed on imaging tests like ultrasound, CT and MRI.  Further testing may be performed with endoscopic ultrasound.  Treatment is surgical for the main duct IPMN and for certain side branch tumors which have high risk features.