Diagnosing bile duct cancer

This page was reviewed under our medical and editorial policy by

Maurie Markman, MD, President, Medicine & Science.

This page was updated on June 3, 2022.

A thorough and accurate bile duct cancer diagnosis is the first step in designing a bile duct cancer treatment plan. A variety of tests and tools is used for diagnosing bile duct cancer, evaluating the disease and customizing a treatment plan for each patient. Throughout treatment, we use imaging and laboratory tests to track the size of the tumors, monitor the response to treatment and modify the treatment plan when needed.

The following procedures are commonly used for diagnosing bile duct cancer (cholangiocarcinoma):

Lab tests

Laboratory tests used for diagnosing bile duct cancer include:

Liver function tests (LFTs): A number of lab tests check for abnormalities in the bile duct, gallbladder or liver, including blood counts of bilirubin, albumin, alkaline phosphatase, aspartate transaminase (AST), alanine transaminase (ALT) and gamma glutamyl transpeptidase (GGT). High levels of these substances in the blood indicate problems with the bile duct, gallbladder or liver.

Blood tests for tumor markers: High blood levels of the carcinoembryonic antigen (CEA) and CA 19-9 tumor markers may be found in people with bile duct cancer. However, other problems with the bile duct can also increase the levels of these tumor markers in the blood, and not all bile duct cancers have these markers. In order to accurately diagnose bile duct cancer, these test results are combined with results from other diagnostic tests.

Endoscopic ultrasound

An endoscopic ultrasound may help the doctor see a more detailed images of the bile duct. A thin, lighted tube with a small video camera is inserted through the mouth and esophagus into the small intestine near the bile duct. In rare cases, a laparoscopic ultrasound, through small incisions in the front of the abdomen may be used to examine the bile duct and other internal organs.


A variety of imaging tests may be used to diagnose bile duct cancer including:

CT scan: A CT (computed tomography) scan provides precise information about the size, shape and position of any tumors in the bile duct or elsewhere in the abdomen, as well as nearby blood vessels. CT scans may also be used to guide a biopsy needle precisely into a suspected tumor (CT-guided needle biopsy).

MRI: MRI, which stands for magnetic resonance imaging, is a scan that may be able to distinguish between benign (noncancerous) and malignant (cancerous) tumors. MRIs may also be used to examine blood vessels in and around the bile duct, a procedure known as MR angiography. A magnetic resonance cholangiopancreatography (MRCP) may also be used during an MRI to image the bile ducts.

Cholangiography: A cholangiogram is an imaging test designed to identify abnormalities in the bile ducts such as a block, narrowing or dilation (widening) of the bile duct. For this procedure, a contrast dye is injected into the body, and then X-rays are taken to reveal bile duct obstructions.

The types of cholangiography procedures that might be used in diagnosing bile duct cancer include:

Endoscopic retrograde cholangiopancreatography (ERCP): This outpatient procedure similar to endoscopic ultrasound to reach the bile or pancreatic duct where X-ray images are taken to recognize the problems in the bile duct. The ERCP procedure may be used to obtain biopsies of tissue or fluid, or to place stents in the bile duct to keep it open.

Percutaneous transhepatic cholangiography (PTC): This outpatient procedure uses a thin, hollow needle to gain access to the bile duct through the skin. X-ray images are taken when the needle passes through the bile ducts. Similar to ERCP, this procedure is used to perform biopsies and place stents in the bile duct. If necessary, a tube may be used to drain bile externally.

Next topic: How is bile duct cancer treated?

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