Q: My mother has been experiencing unusual and persistent fatigue, abdominal pain and jaundice. After undergoing a CT scan, her doctor diagnosed her with cholangiocarcinoma. What is this type of cancer?

A: Cholangiocarcinoma is a rare cancer that develops from the bile ducts, which are tubes that carry the digestive fluid bile and connect the liver to the gallbladder and small intestine.

The tumor can occur anywhere along the biliary “tree” and is divided into three subtypes based on where it starts.

The intrahepatic subtype starts in the bile duct inside the liver and typically appears as a mass in the liver, which may affect the organ’s function.

The second subtype, called perihilar cholangiocarcinoma, occurs just outside the liver, where the bile ducts come together and exit the liver. Patients diagnosed with this subtype typically present with jaundice.

Distal cholangiocarcinoma is the third subtype. It occurs in the portion of the bile duct that is outside the liver and nearest to the intestine. This subtype also typically presents with jaundice.

An initial CT scan can be suggestive of cholangiocarcinoma, but additional testing, including a biopsy or brushings, is needed to establish the diagnosis and stage. For all subtypes, a health care professional also will order a CT scan of the chest to look for any signs of metastasis, or spread, to the lungs.

If there is blockage of the bile ducts and jaundice, symptoms most commonly occurring with the perihilar or distal subtypes, then a health care professional may perform an endoscopic evaluation. This allows for collection of a sample of the area of concern and placement of an internal stent to open the bile ducts so the liver can drain appropriately.

Biliary drainage helps relieve symptoms of biliary blockage, which can include jaundice, poor appetite and itching.

For intrahepatic tumors that present as a liver mass, it is common to have an ultrasound-guided biopsy to establish the diagnosis and obtain tissue for further testing.

There are many options for treating these rare tumors, but determining the best approach for your mother will depend on the stage, location and subtype of her tumor.

For example, most patients with localized disease, meaning the cancer has not spread to any other organs, are candidates for surgery to remove the tumors.

If your mother is diagnosed with intrahepatic or perihilar cholangiocarcinoma, removing part of the liver may be required.

However, standard surgical approaches to remove the tumor may not be possible for some patients diagnosed with perihilar cholangiocarcinoma. A liver transplant may be an option instead.

The most common surgery to treat distal cholangiocarcinoma is called the Whipple procedure, which is a complex operation that involves removing part of the pancreas.

For patients who are not able to have surgery, other treatments should be considered, like chemotherapy, targeted therapy, immunotherapy, radiation and radioembolization. These treatments often are given in combination.

As part of the testing for patients diagnosed with cholangiocarcinoma, it is now common to perform an analysis for mutations, called next-generation sequencing.

These tests can identify certain mutations in tumors for which we have targeted therapy options, and these mutations occur more frequently in intrahepatic cholangiocarcinoma.

If your mother has been diagnosed with cholangiocarcinoma, it is crucial that she go to a cancer center with a specialty in treating these tumors because the treatments, and determining which patients are candidates, is complex. — Rory Smoot, M.D., Surgery, Mayo Clinic, Rochester, Minnesota

Mayo Clinic Q&A is an educational resource and doesn’t replace regular medical care. Email a question to MayoClinicQ&A@mayo.edu.