Lung Cancer: Diagnosis

March 21, 2017

Lung Cancer: Diagnosis

How is lung cancer diagnosed?

If your healthcare provider thinks you may have lung cancer, you will need certain exams and tests to be sure. Diagnosing lung cancer starts with your healthcare provider asking you questions. He or she will ask you about your health history, your symptoms, risk factors, and family history of disease. Your provider will also give you a physical exam. He or she might also:

  • Give you a sputum cytology test. For this test, each morning for 3 to 5 days, you collect the substance (sputum) that you spit up from your lungs. The provider looks at the sputum under a microscope for cancer cells. Not all types of lung cancer show up in this test.

  • Schedule an X-ray of your chest to look for masses in your lungs.

  • Arrange for other imaging tests to get a better picture of your lungs. This may include a CT scan and also perhaps an MRI test.

Any of these tests might suggest that you have lung cancer. But if imaging tests show abnormal findings, such as a mass or fluid, you may need to have a sample taken. This sample (biopsy) is almost always needed to diagnose lung cancer. The method used to get a biopsy sample is determined partly by where the tumor is and how large it is. 

What tests might I need?

Your doctor may suggest that you have one or more of the following tests to help diagnose lung cancer. After any kind of biopsy, the doctor looks at the biopsy samples under a microscope to check for cancer cells. It usually takes several days for the results of your biopsy to come back. Along with telling if you have lung cancer, a biopsy can usually tell what kind of lung cancer it is.

Your doctor can take a biopsy of your lung in several ways:

  • Bronchoscopy

  • Needle biopsy

  • Thoracentesis

  • Thoracotomy or thoracoscopy 

Each is described below.


A doctor called a pulmonologist usually does this test. This doctor is one who specializes in lung diseases. To get the cells for this type of biopsy, the doctor uses a long, thin, lighted tube called a bronchoscope. It may be flexible or rigid. The tube goes through your mouth or nose, into your breathing passages, and into the lungs. It has a tiny video camera on the end so that your doctor can see inside your lungs to get the cells.

How it is done

This procedure usually takes about an hour. If your doctor is using a flexible bronchoscope, he or she sprays a local numbing medicine (anesthesia) inside your nose or mouth. You may feel as if fluid is running down your throat. It may make you cough or gag. That feeling will stop when the numbness kicks in. You may also have an IV with medicine to help you relax. If your doctor uses a rigid bronchoscope, you will get general anesthesia so that you will sleep during the test.

With either type of bronchoscopy, your doctor puts a saltwater solution (saline) into the lung passageways. This liquid flushes the area and helps collect cells, fluids, and other materials in your airways. Your doctor may also put tiny brushes, needles, or forceps through the bronchoscope to collect cells from any suspicious-looking areas. He or she will send all the collected samples to a lab to be checked for cancer.

As the numbing medicine wears off, your throat may feel scratchy. You won’t be able to eat for several hours. You will need to have someone drive you home. Some people want to rest the day after the biopsy. So you may want to take the day off from your usual activities.

Needle biopsy

This is also called needle aspiration or transthoracic needle aspiration. Your doctor may use this test if your tumor can’t be reached easily by a bronchoscope. The doctor puts a thin, hollow needle through your chest and into the tumor to remove some tissue. Often you will have an X-ray or CT scan at the same time. That helps the doctor see the tumor and guide the needle. 

How it is done

This procedure is usually done by a doctor called an interventional radiologist. You may have a chest X-ray or a chest CT scan to help your doctor see exactly where to take the cells. If you are getting an X-ray, you will sit with your arms resting on a table. If you are getting a CT scan, you will lie down. In either case, it’s important that you don’t move. You may get medicine to help you stay still. The doctor numbs your skin by injecting medicine. To get the needle in, the doctor may need to make a very small cut in your skin. You will feel pressure and a short, sharp pain when the needle touches your lung. The needle goes into the tumor or abnormal tissue and draws out cells. The doctor puts pressure until the bleeding has stopped and then covers the site with a bandage. The doctor sends the collected cells to a lab to be checked for cancer. Right after the biopsy, you will have a chest X-ray. This is to make sure there are no complications, such as a collapsed lung (pneumothorax). You may be able to drive yourself home after the test.


This is also called a pleural fluid aspiration or a pleural tap. It can be done if you have fluid around your lungs to see if the fluid contains cancer cells. To get the fluid, the doctor puts a hollow needle into the skin between your ribs. This test may be done to diagnose lung cancer. Or it can be done to drain fluid if it is making you short of breath.

How it is done

You will lie on a bed. Or you may sit on the edge of the bed or a chair and rest your head and arms on a table. The doctor injects medicine into your skin on your chest or back to numb the area. Then the doctor inserts the thoracentesis needle. It goes above a rib into the space between the lining of the outside of your lungs and your chest wall (pleural space). You may feel pressure. Your doctor sends the collected fluid to a lab to be checked for cancer. You may be able to drive yourself home after the test.


A thoracotomy is a type of surgery. It is done in an operating room. The surgeon opens up your chest to look for lung cancer. This is usually done when the doctor can’t make the diagnosis by any of the other methods. If possible, the surgeon removes the entire tumor during a thoracotomy.    

How it is done

You must check into the hospital for a thoracotomy. On the day of your surgery, you get medicine so you will sleep through the surgery. You won’t feel anything. The surgeon cuts between your ribs to reach your lungs and look for diseased tissue. The doctor takes out some of the diseased tissue and sends it to a lab to be checked for cancer. When you wake up, you will have a tube in your chest to drain air, fluid, and blood. You may need to stay in the hospital for a couple of days. During that time, you will get pain medication.

A similar but slightly less invasive procedure is a thoracoscopy. The surgeon can use this to look at and take a biopsy of the outer surface or the linings of the lungs and other nearby structures. Like a thoracotomy, you get medicine so that you will sleep during the surgery. But instead of making one long incision, the surgeon makes a few small cuts in the chest wall. The surgeon puts a long, thin instrument with a small video camera on the end through one of the cuts to let him or her see. The surgeon also puts special instruments through the other cuts to sample any abnormal areas. Because the incisions are smaller, people usually recover quicker from this type of procedure.

Getting your test results

When your healthcare provider has the results of your biopsy, he or she will contact you. Your provider will talk with you about other tests you may need if lung cancer is found. Make sure you understand the results and what follow-up you need.   


March 21, 2017


Overview of the initial evaluation, diagnosis, and staging of patients with suspected lung cancer. UpToDate.

Reviewed By:  

Alteri, Rick, MD,Gersten, Todd, MD