Based on what you tell the doctor about your symptoms, he or she will ask questions about them; your medical and surgical history; smoking and work history; and other issues such as lifestyle, overall health, and the medications you've taken.
As long as you're not spitting up blood, your doctor will most likely ask for a chest X-ray to look for a cause of the respiratory symptoms. The X-ray may or may not show an abnormality. Types of abnormalities seen on chest X-rays include a small nodule or nodules or a large mass. Not all abnormalities are cancers. For example, some people develop scarring and calcium deposits in their lungs that may look like tumors.
If your symptoms are severe, the doctor may skip the X-ray and ask for a CT scan or MRI. In most cases, a CT scan or MRI of the chest will more clearly define the problem. The advantages of a CT scan or an MRI are that they show much greater detail than an X-ray and the images are in 3 dimensions. These tests help determine the stage of the cancer by showing the size of the tumor or tumors. They can also help identify any spread of the cancer into regional lymph nodes or certain other organs.
If your X-ray or scan suggests a tumor is present, you will undergo a procedure for diagnosis. This involves removal of a small piece of the tumor tissue (biopsy) or a small volume of fluid from the sac around the lung. The cells are then reviewed under a microscope by a doctor, called a pathologist, who specializes in diagnosing diseases by looking at cell and tissue types.
These cells may be obtained in several different ways:
Sputum testing This is a simple test that is sometimes performed to detect cancer in the lungs. Sputum is a thick mucus that may be produced during a cough. Cells in the sputum can be examined to see if they are cancerous. This test is called cytologic review. It's not a completely reliable test. If the results are negative, the findings still need to be confirmed by other tests.
Bronchoscopy This is a test done with a thin, flexible, lighted tube -- called a bronchoscope -- that has a tiny camera on the end that's used to view organs inside your body. The tube is inserted through the mouth or nose and down the windpipe. From there, it can be inserted into the airways (bronchi) of the lungs. The procedure can be uncomfortable. A local anesthetic for the mouth and throat as well as sedation will be used to make procedure tolerable
The camera transmits images back to a video monitor. The doctor can look for tumors and collect samples of any suspected tumors. The test can usually determine the extent of the tumor. Bronchoscopy has some risks and requires a specialist proficient in doing it.
Needle biopsy If a tumor is on the periphery of the lung, it usually cannot be seen with bronchoscopy. Instead, a biopsy may often be taken through a needle inserted through the chest wall and into the tumor. Typically, a chest X-ray or CT scanning is used to guide the needle. This procedure is usually safe and effective in obtaining sufficient tissue for diagnosis.
After the chest surface is cleaned and prepared, the skin and the chest wall are numbed. The most serious risk is that the needle puncture may cause an air leak from the lung (pneumothorax). This air leak occurs in as many as 20% of cases. Many are so small, though, that they don't need treatment. Only about 3% will require a chest tube. Although the leak can be dangerous, it is almost always recognized and treated without serious consequences.
ThoracentesisLung cancers, both primary and metastatic, can cause fluid to collect in the sac surrounding the lung. This is called pleural effusion. The fluid usually contains cancer cells. Sampling this fluid can confirm the presence of cancer in the lungs. The fluid sample is removed by a needle in a procedure similar to needle biopsy. Thoracentesis can be important for both staging and diagnosis of the condition.
Thoracotomy Sometimes a lung cancer tumor cannot be reached by bronchoscopy or needle procedures. In these cases, the only way to get a biopsy is with an operation. Lung surgery is performed by thoracotomy or video-assisted thoracoscopic surgery (VATS). During the procedure, as much of the tumor as possible is removed, and a biopsy is taken from the removed tumor. Unfortunately, this operation may not be successful in removing all tumor cells, especially if the tumor is large or has spread to the lymph nodes outside of the lungs. Thoracotomy and VATS are both major operations that are performed in a hospital.
Mediastinoscopy This is another endoscopic procedure. It is performed to determine the extent that the cancer has spread into the area of the chest between the lungs (the mediastinum). A small incision is made into the lower part of the neck, above the breastbone (sternum). A variation is to make the incision in the chest. A mediastinoscope is inserted behind the breastbone. Samples of the lymph nodes are taken to evaluate for cancer cells. Mediastinoscopy is a very important step to determine whether the tumor can be surgically removed or not.