How Is Cancer of the Esophagus Diagnosed?

Esophagus cancers are usually found because of signs or symptoms a person is having. If esophagus cancer is suspected, exams and tests will be needed to confirm the diagnosis. If cancer is found, further tests will be done to help determine the extent ( stage) of the cancer.

Medical history and physical exam

If you have symptoms that might be caused by esophageal cancer, the doctor will ask about your medical history to check for possible risk factors and to learn more about your symptoms.

Your doctor will also examine you to look for possible signs of esophageal cancer and other health problems. He or she will probably pay special attention to your neck and chest areas.

If the results of the exam are abnormal, your doctor probably will order tests to help find the problem. You may also be referred to a gastroenterologist (a doctor specializing in digestive system diseases) for further tests and treatment.

Imaging tests

Imaging tests use x-rays, magnetic fields, sound waves, or radioactive substances to create pictures of the inside of your body. Imaging tests might be done for a number of reasons both before and after a diagnosis of esophageal cancer, including:

  • To help find a suspicious area that might be cancer
  • To learn if and how far cancer has spread
  • To help determine if the treatment has been effective
  • To look for possible signs of cancer coming back after treatment

Barium swallow

In this test, a thick, chalky liquid called barium is swallowed to coat the walls of the esophagus. X-rays of the esophagus are then taken, which the barium outlines clearly. This test can be done by itself, or as a part of a series of x-rays that includes the stomach and part of the intestine, called an upper gastrointestinal (GI) series. A barium swallow test can show any abnormal areas in the normally smooth surface of the inner lining of the esophagus.

This is often the first test done to see what is causing a problem with swallowing. Even small, early cancers can often be seen using this test. Early cancers can look like small round bumps or flat, raised areas (called plaques), while advanced cancers look like large irregular areas and cause a narrowing of the width of the esophagus.

This test can also be used to diagnose one of the more serious complications of esophageal cancer called a tracheo-esophageal fistula. This occurs when the tumor destroys the tissue between the esophagus and the trachea (windpipe) and creates a hole connecting them. Anything that is swallowed can then pass from the esophagus into the windpipe and lungs. This can lead to frequent coughing, gagging, or even pneumonia. This problem can be helped with surgery or an endoscopy procedure.

A barium swallow only shows the shape of the inner lining of the esophagus, so it can’t be used to determine how far a cancer may have spread outside of the esophagus.

Computed tomography (CT or CAT) scan

The CT scan uses x-rays to produce detailed cross-sectional images of your body. CT scans are not usually used to diagnose esophageal cancer, but they can help show where it is in the esophagus and if it has spread to nearby organs and lymph nodes (bean-sized collections of immune cells to which cancers often spread first) or to distant parts of the body. The CT scan can help to determine whether surgery is a good treatment option.

A CT scanner has been described as a large donut, with a narrow table that slides in and out of the middle opening. You will need to lie still on the table while the scan is being done. CT scans take longer than regular x-rays, and you might feel a bit confined by the ring while the pictures are being taken. Instead of taking one picture, like a standard x-ray, a CT scanner takes many pictures as it rotates around you. A computer then combines these pictures into an image of a slice of your body.

Before the test, you may be asked to drink 1 to 2 pints of a liquid called oral contrast. This helps outline the esophagus and intestines so that certain areas are not mistaken for tumors. If you are having any trouble swallowing, you need to tell your doctor before the scan. You might also receive an IV (intravenous) line through which a different kind of contrast dye (IV contrast) is injected. This helps better outline structures in your body.

The injection can cause some flushing (redness and warm feeling, especially in the face). Some people are allergic to the dye and get hives. Rarely, more serious reactions like trouble breathing and low blood pressure can occur. Be sure to tell your doctor if you have any allergies or have ever had a reaction to any contrast material used for x-rays. You can be given medicine to help prevent and treat allergic reactions.

CT-guided needle biopsy: CT scans can also be used to guide a biopsy needle precisely into a suspected area of cancer spread. For this procedure, you remain on the CT scanning table while the doctor advances a biopsy needle through the skin and toward the tumor. CT scans are repeated until the needle is within the mass. A needle biopsy sample is then removed to be looked at under a microscope.

Magnetic resonance imaging (MRI) scan

Like CT scans, MRI scans provide detailed images of soft tissues in the body. But MRI scans use radio waves and strong magnets instead of x-rays. The energy from the radio waves is absorbed and then released in a pattern formed by the type of body tissue and by certain diseases. A computer translates the pattern of radio waves given off by the tissues into a very detailed image of parts of the body. A contrast material might be injected into a vein. This contrast is different than the one used for CT scans, so being allergic to one doesn’t mean you are allergic to the other.

MRI scans are very helpful in looking at the brain and spinal cord, but they are not often needed to assess spread of esophageal cancer.

MRI scans take longer than CT scans – often up to an hour – and are a little more uncomfortable. You have to lie on a table that slides inside a narrow tube, which is confining and can upset people with a fear of enclosed spaces. Special, more open MRI machines can sometimes help with this if needed, although the images may not be as sharp in some cases. MRI machines make buzzing and clicking noises that you may find disturbing. Some centers provide earplugs to help block this noise out.

Positron emission tomography (PET) scan

For a PET scan, a form of radioactive sugar (known as fluorodeoxyglucose or FDG) is injected into the blood. The amount of radioactivity used is very low and will pass out of the body over the next day or so. Cancer cells in the body are growing rapidly, so they absorb large amounts of the radioactive sugar. After about an hour, you will be moved onto a table in the PET scanner. You lie on the table for about 30 minutes while a special camera creates a picture of areas of radioactivity in the body. The picture is not finely detailed like a CT or MRI scan, but it provides helpful information about your whole body.

This type of scan may be used to look for possible areas of cancer spread if nothing is found on other imaging tests.

Special machines can do both a PET and CT scan at the same time (PET/CT scan). This lets the doctor compare areas of higher radioactivity on the PET scan with the more detailed appearance of that area on the CT scan.


An endoscope is a flexible, narrow tube with a tiny video camera and light on the end that is used to look inside the body. Tests that use endoscopes can help diagnose esophageal cancer or determine the extent of its spread.

Upper endoscopy

This is an important test for diagnosing esophageal cancer. During an upper endoscopy, you are sedated (made sleepy) and then the doctor passes the endoscope down the throat and into the esophagus and stomach. The camera is connected to a monitor, which lets the doctor see any abnormal areas in the wall of the esophagus clearly.

The doctor can use special instruments through the scope to remove (biopsy) samples from any abnormal areas. These samples are sent to the lab so that a doctor can look at them under a microscope to see if they contain cancer.

If the esophageal cancer is blocking the opening (called the lumen) of the esophagus, certain instruments can be used to help enlarge the opening to help food and liquid pass.

Upper endoscopy can give the doctor important information about the size and spread of the tumor, which can be used to help determine if the tumor can be removed with surgery.

Endoscopic ultrasound

This test is usually done at the same time as the upper endoscopy, although it is actually a type of imaging test. Ultrasound tests use sound waves to take pictures of parts of the body.

For an endoscopic ultrasound, a probe that gives off sound waves is at the end of an endoscope, which is passed down the throat and into the esophagus. This allows the probe to get very close to tumors in the esophagus or nearby.

The probe sends out sound waves, and the echoes are picked up by the probe. A computer turns the pattern of sound waves into a black-and-white image showing how deeply the tumor has grown into the esophagus. It can detect small abnormal changes very well.

This test is very useful in determining the size of an esophageal cancer and how far it has grown into nearby areas. It can also help show if nearby lymph nodes might be affected by the cancer. If enlarged lymph nodes are seen in the chest on the ultrasound, the doctor can pass a thin, hollow needle through the endoscope to get biopsy samples of them. This helps the doctor decide if the tumor can be removed with surgery.


This exam may be done for cancer in the upper part of the esophagus to see if it has spread to the windpipe (trachea) or the tubes leading from the windpipe into the lungs (bronchi).

For this test, a lighted, flexible fiber-optic tube (bronchoscope) is passed through your mouth or nose and down into the windpipe and bronchi. The mouth and throat are sprayed first with a numbing medicine. You may also be given medicine through an intravenous (IV) line to make you feel relaxed.

If abnormal areas are seen, small instruments can be passed down the bronchoscope to take biopsy samples.

Thoracoscopy and laparoscopy

These exams let the doctor see lymph nodes and other organs near the esophagus inside the chest (by thoracoscopy) or the abdomen (by laparoscopy) through a hollow lighted tube.

These procedures are done in an operating room while you are under general anesthesia (in a deep sleep). A small cut (incision) is made in the side of the chest wall (for thoracoscopy) or the abdomen (for laparoscopy). Sometimes more than one cut is made. The doctor then inserts a thin, lighted tube with a small video camera on the end through the incision to view the space around the esophagus. The surgeon can pass thin instruments into the space to remove lymph node and biopsy samples to see if the cancer has spread. This information is often important in deciding whether or not a person is likely to benefit from surgery.

Lab testing of biopsy samples

An area seen on endoscopy or on an imaging test may look like cancer, but the only way to know for sure is to do a biopsy. For a biopsy, the doctor removes small pieces of tissue from an abnormal area. This is most often done during an endoscopy exam.

A doctor called a pathologist then looks at the tissue under a microscope to see if it contains cancer cells. If there is cancer, the pathologist will determine the type (adenocarcinoma or squamous cell) and the grade of the cancer (how abnormal the patterns of cells look under the microscope). For details about grading, see “ How is cancer of the esophagus staged?” It can often take a few days to get the results of a biopsy.

HER2 testing: If esophageal cancer is found but is too advanced for surgery, your biopsy samples may be tested for the HER2 gene or protein. Some people with esophageal cancer have too much of the HER2 protein on the surface of their cancer cells, which helps the cells grow. A drug that targets the HER2 protein, known as trastuzumab (Herceptin®), may help treat these cancers when used along with chemotherapy. Only cancers that have too much of the HER2 gene or protein are likely to be affected by this drug, which is why doctors may test tumor samples for it. (See “ Targeted therapy for cancer of the esophagus” for more information on this treatment.)

Other tests

When looking for signs of esophageal cancer, a doctor may order a blood test called a complete blood count (CBC) to look for anemia (a low red blood cell count, which could be caused by internal bleeding). A stool sample may be checked to see if it contains occult (unseen) blood.

If esophageal cancer is found, the doctor may order other tests, especially if surgery might be an option. For instance, blood tests can be done to make sure your liver and kidneys are working normally. Tests may also be done to check your lung function, since some people might have lung problems (such as pneumonia) after surgery. If surgery is planned or you are going to get medicines that could affect your heart, you may also have an electrocardiogram (EKG) and echocardiogram (ultrasound of the heart) to make sure your heart is working well.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: March 20, 2014 Last Revised: February 4, 2016

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