Diagnosing Lung Cancer

It May Come as a Shock

Unfortunately, lung cancer may be present for years before it is diagnosed, because patients initially may not have any obvious signs or symptoms.

When lung cancer is suspected, a full health history, a physical exam, and a series of diagnostic tests are performed. Click on any of the links below to find a specific topic on this page.

Symptoms
Health history
Physical exam
Diagnostic tests

Recognizing Symptoms of Lung Cancer

There are many symptoms of lung cancer. However, most of these symptoms are easily overlooked or are thought to be caused by something else because people with other conditions may experience them as well:

• Cough that doesn't go away
• Shortness of breath during regular daily activities
• Feeling tired all the time
• Chest pain
• Blood in the sputum
• Tingling/"pins and needles" down the arms
• Pain in the shoulder/arm or arm pit
• Repeated pneumonia or bronchitis
• Unexplained loss of appetite and/or weight
• Hoarseness
• Wheezing
• Swelling of face or neck

Providing a Full Health History

One of the most important steps in diagnosing lung cancer is providing a full health history. Telling your healthcare provider about your smoking history, family members with cancer, environmental factors, and exposure to toxic substances, such as asbestos and radon, can help him or her determine your risk of lung cancer.

Taking a Physical Exam

If your doctor suspects lung cancer, he or she will probably have you take a physical exam. During the exam, your healthcare provider will most likely listen to your lungs for any abnormal sounds and check your lymph nodes for swelling.

The next step will be to take a series of diagnostic tests.

Undergoing Diagnostic Testing

In order to diagnose lung cancer, a variety of tests may be performed. Your doctor will decide which tests are appropriate for you. Tests your doctor may order include a chest x-ray, computerized tomography (CT) scan, magnetic resonance imaging (MRI), positron emission tomography (PET) scan, and sputum cytology. Sometimes, special blood tests are done to look for genetic markers of lung cancer.

Chest X-ray
Chest x-ray is the most common test used to diagnose lung cancer. A picture is taken of your chest that can show if there is a mass present or if there is an abnormal widening between the lungs. Having more than one chest x-ray can help your healthcare provider compare the images to determine any changes in tumor size over time.

Computerized Tomography and Magnetic Resonance Imaging
CT and MRI scans take 3-dimensional images of the organs and can show the size, shape, and location of a tumor. They also can find enlarged lymph nodes that may contain cancer cells. The CT scan is often performed after a chest x-ray.

Positron Emission Tomography Scan
Like CT and MRI scans, a PET scan is another imaging test. However, PET measures the way that cells function rather than show abnormal cell structure. A radioactive sugar solution is injected into the bloodstream, and the PET scan shows how quickly the sugar is used. Cancerous cells in the lung use sugar faster than normal cells. This scan is helpful as a follow-up to x-ray, CT, or MRI scans because it helps determine whether or not a mass is cancerous.

Sputum Cytology
Sputum is the fluid coughed up from the lungs. Sputum cytology involves looking at the cells in the sputum under a microscope to determine whether cancer cells are present. This test, however, does not show the size or location of a tumor.

Blood Samples
Blood tests may be ordered as part of the diagnostic process. Samples of blood are taken from a vein in the arm and are then studied in a laboratory for:

• Liver function
• Kidney function
• Blood cell counts

Biopsy
A biopsy is a test in which a sample of the patient's tumor is removed and studied under a microscope. The results of a biopsy determine whether a tumor is cancerous. Tissue for biopsy may be removed in the following procedures:

• Bronchoscopy
  During a bronchoscopy, a special device, called a bronchoscope, is put down the throat and into the lung. This lets your doctor look directly at a tumor in the large airway and remove a piece of it for biopsy. Patients sometimes cough but generally tolerate this procedure well, and it is sometimes performed without anesthesia.
  
  A new technique, called fluorescence bronchoscopy, involves injecting dye into the bloodstream. A special laser is then used to determine if the cells have absorbed the dye in a normal way. If the cells do not absorb the dye in a normal way, they are removed and tested for cancer.
  
  
• Mediastinoscopy
  During a mediastinoscopy, the patient is put under anesthesia, a small incision is made in the neck or chest, a tube that the doctor can look through is inserted, and a tissue sample is taken. This procedure is most often done to biopsy the lymph nodes in the chest and determine whether the cancer has spread.
  
  
• Thoracoscopy
  A thoracoscopy is the examination of the chest cavity with an instrument called an endoscope. The patient is put under anesthesia and an endoscope is inserted through the skin into the space between the chest wall and the lungs. The tumor is visualized with the endoscope and biopsied. This procedure may be performed with a small video camera. This is called video-assisted thoracoscopic surgery (VATS).
  
  
• Thoracotomy
  Thoracotomy is a major surgical procedure during which the patient is put under anesthesia, the chest is opened, and the lungs are looked at directly. This procedure may be performed if other tests have not been conclusive and if your doctor strongly suspects that cancer is present. In some cases, both diagnosis and treatment are performed during a thoracotomy.

Choose a link below for more information about the types, stages, and treatment of lung cancer.

Types of Lung Cancer
Stages of Lung Cancer
Treating Lung Cancer
More Information