Diagnosing Lung Cancer

father and sonThe method to diagnose lung cancer is different for each person. Your medical team chooses tests based on a number of factors:

  • your medical history
  • your symptoms
  • findings from your physical exam

Your doctor might order imaging tests that may help find lung cancer. Imaging tests make pictures of the inside of your body. These pictures help doctors to find lung cancer, to see if it has spread, to see if treatment is working or to find a cancer that has come back after treatment. These tests include:

  • CT scan (computed tomography)A CT (or CAT) scan is a special kind of x-ray that takes many pictures as you lie on a table that slides in and out of the machine. A computer then combines these pictures into a detailed picture of a slice of your body.
  • PET scan (positron emission tomography)For a PET scan, a form of radioactive sugar is injected into the blood. Cancer cells in the body absorb large amounts of the sugar. A special camera can then spot the radioactivity. This test can help show whether the cancer has spread to the lymph nodes or other parts of the body.
  • Bone scanA small, safe amount of radioactive substance is put into your vein. This substance builds up in areas of bone that may not be normal because of cancer. These areas show up as dense, gray to black areas, called “hot spots.” These areas may indicate cancer.

To see if something suspicious is actually lung cancer, the doctor must study tissue or fluid from the lung. Many different procedures allow doctors to remove cells from the body and look at them under a microscope to determine if they are cancer. These tests include:

  • BronchoscopyA lighted, flexible tube (called a bronchoscope) is passed through the mouth or nose and into the larger airways of the lungs. This test can help the doctor see tumors, or it can be used to take samples of tissue or fluids to see if cancer cells are present.
  • Endobronchial ultrasoundFor endobronchial ultrasound, a bronchoscope (a thin, lighted, flexible tube) is fitted with an ultrasound device (a device that uses sound waves to make pictures of the inside of your body) at its tip. It is passed down into the windpipe to look at nearby lymph nodes and other structures in the chest. This is done with numbing medicine (local anesthesia) and light sedation. A hollow needle can be passed through the bronchoscope and guided by ultrasound into an area of concern to take biopsy samples.
  • Endoscopic esophageal ultrasoundThis test is much like an endobronchial ultrasound, except that an endoscope (a lighted, flexible tube) is used. It is passed down the throat and into the esophagus.
  • Mediastinoscopy and mediastinotomyBoth of these tests let the doctor look at and take samples of the structures in the area between the lungs (this area is called the mediastinum).
  • ThoracentesisThis test is done to check whether fluid around the lungs is caused by cancer or by some other medical problem. A needle is placed between the ribs to drain the fluid. The fluid is checked for cancer cells.
  • ThoracoscopyA small cut is made in your chest. The doctor then uses a thin, lighted tube connected to a video camera and screen to look at the space between the lungs and the chest wall. The doctor can see small tumors on the lung or lining of the chest wall and can take out pieces of tissue to be looked at under the microscope. Thoracoscopy can also be used as part of the treatment to remove part of a lung in some early-stage lung cancers.
  • Sputum cytologyA sample of mucus you cough up from the lungs (called sputum or phlegm) is looked at under a microscope to see if cancer cells are present.
  • Fine needle biopsy (FNA)A long, thin (fine) needle is used to remove a sample of cells from the area that may be cancer. The sample is looked at in the lab to see if there are cancer cells in it.

There are some tests being developed that show promise in the early detection of lung cancer. Many researchers are working to develop tests that can make a difference in early lung cancer screening and survival.

If you are a current or former smoker AND/OR have any symptoms, talk to your doctor about tests to see if you have lung cancer.

In addition to screening for lung cancer, staging lung cancer and tumor testing are two important topics to understand that will help you know what kind of lung cancer you have.

Screening for Lung Cancer

CT scan

Screening is looking for cancer before a person has any symptoms. This can help find cancer at an early stage when it may be easier to treat. Screening may provide new hope for early detection and treatment of lung cancer. » More


Doctor looking at chest x-ray

Staging is part of the diagnosis and determines largely what your recommended treatment plan may be. Staging means finding out if and how much the lung cancer has spread. This is important because your treatment and the general outlook for your recovery and chance of cure depend upon the stage of your lung cancer. » More

Tumor Testing

cell culture

More detailed testing can be done on your tumor if your doctor requests it. These tests, sometimes referred to as molecular testing, look for changes (mutations) in the DNA of the tumor and levels of specific proteins present in the tumor. When doctors have this information, they may choose to administer specialized therapies that target the mutation in the cells. » More



Early detection of lung cancer can increase survival rates. Call the Lung Helpline at 1-800-LUNGUSA or talk to your doctor about lung cancer screening.