If your doctor suspects you might have lung cancer, a number of diagnostic tests will be performed to look for cancer cells and rule out other possible conditions.

These tests include:

Sputum Cytology

If you have a productive cough, your doctor may examine a sample of sputum under a microscope to look for lung cancer cells.

Blood Tests

Complete blood counts (CBC) and blood chemistry tests are used to watch for any abnormal findings that may be caused by lung cancer.

Radiology and Imaging

A variety of imaging tests can help your doctor determine the presence of cancer.

Magnetic Resonance Imaging (MRI): MRI uses radio waves and a large magnet to create an internal image. This exam is often used to find lung cancer that has spread to the brain or spinal cord.

Computed tomography (CT):A CT scan uses x-rays to take an internal picture. Instead of taking just one picture, as a normal chest x-ray does, a CT scanner takes many pictures as it rotates. A computer then combines all the pictures and creates images that are like "slices" of your body. CT images can give doctors precise information about tumors, including shape, size, and location.

Positron Emission Tomography (PET):In a PET scan, a specially-labeled substance is injected that is absorbed in large amounts by cancer cells. This substance is then detected by a special camera. The image produced indicates areas with large amounts of the substance. Doctors can use the image to find lung cancer that has spread to other areas of the body.

Bone Scan:Doctors may use a bone scan to determine whether or not lung cancer has spread to the bones. Areas of diseased bone will show up differently on the scan.


A biopsy is a procedure in which a small sample of tissue is removed to examine it for cancer cells. Lung biopsies can be performed in several different ways.

Fine needle biopsy: A needle is guided into the lungs and a sample of cells is removed; this sample is then examined for the presence and characteristics of cancer.

Bone marrow biopsy: A small piece of bone and a sample of bone marrow are removed; these samples are used to detect metastasis (spread) to the bones. This is only done for SCLC.

Bronchoscopy: A lighted, flexible tube is passed into the bronchi; this is used to find tumors and take samples of cells and fluid.

Mediastinoscopy: A lighted tube is inserted under the breastbone through a small cut in the neck, allowing doctors to take a sample of regional lymph nodes.

Thoracentesis: A needle is placed through the ribs to drain fluid; the fluid is checked for the presence of cancer cells.

Thorascopy: A thin, lighted tube with a video camera is inserted into the space between the lungs and chest wall, allowing doctors to check the surface of the lungs.


Once tissue samples have been removed, a pathologist will examine them under a microscope to determine the presence, type and extent of the cancer. The pathologist will then compile what’s called a pathology report, which your doctor will use to help decide on a treatment plan.

Interventional Pulmonology

Interventional pulmonology represents a major leap forward in early detection of lung cancer. New, non-invasive procedures are able to find lung abnormalities that are too small or too deep within the lungs to be detectable with traditional scanning methods. Interventional pulmonology is available for patients at high risk for developing primary or recurrent lung cancer.

Staging Lung Cancer

Treatment decisions are based in large part on the stage, or extent, of the cancer. Non-small cell lung cancer is commonly staged using the TNM staging method. T refers to tumor size (how big the tumor is and whether it has spread in the area), N refers to lymph nodes (are any lymph nodes positive for cancer, and if so how many), and M refers to metastasis (has the cancer spread to other parts of the body).

Learn more about lung cancer staging.