Following a lung cancer diagnosis, you may be wondering what’s going on inside your body. Understanding what the cancer cells look like, as well as the types of imaging tools used to view them, can boost your understanding of what’s happening inside your body during your journey with this condition.

A health care provider uses a variety of techniques to visualize lung cancer cells and the affected organs. Visualizing disease allows doctors to distinguish different types of lung cancer and determine how far the disease has spread.

Lung Cancer Under a Microscope

To confirm a diagnosis of lung cancer, a doctor will need to observe tissue samples under a microscope to look for evidence of cancer cells. There are different types of procedures to obtain samples for analysis:

• Tissue needle biopsy, which involves removing a portion of affected tissue so it can be analyzed
• Sputum cytology, which allows your health care team to analyze your sputum (mucus)
• Thoracentesis, which is used to collect fluid from around the lungs
• Mediastinotomy, a surgical procedure to remove tissue from the space between the lungs and breastbone, known as the mediastinum

Following sample collection, analysis under a microscope allows members of your health care team to look at different features to better understand your cancer.

Types of Lung Cancer

The way cancer cells look under a microscope can reveal what type of lung cancer a person has: small cell lung cancer (SCLC) or non-small cell lung cancer (NSCLC). In SCLC, the cells have a very particular appearance under the microscope. When SCLC is ruled out, the cancer is designated as NSCLC.

NSCLC is the most common type of lung cancer. The most common subtype of NSCLC is lung adenocarcinoma, which is defined by cancer cells that look like mucous-producing gland cells. A less common subtype is squamous cell carcinoma, which has flat-looking cancer cells.

Lung Cancer on X-rays

A chest X-ray is one the first imaging tests performed by a doctor to diagnose lung cancer. It exposes the chest to controlled beams of radiation. Tissue blocks radiation to different degrees based on how dense it is, which shows up on a black and white image. A normal, healthy lung will appear mostly dark gray. However, tumor tissue is denser and blocks more radiation, resulting in a lighter gray area relative to the rest of the lung.

Lung Cancer on CT Scans

Computed tomography (CT) is another imaging technique. It uses X-rays to take images at multiple angles. This results in a more detailed, cross-sectional image of the body. Similar to a standard X-ray, areas with dense tissue (such as a tumor) appear on CT scans as a light gray to white mass on the image. A lung without disease will appear only as dark gray to black, with no evidence of a mass.

CT scans can help doctors determine the stage of lung cancer, which is crucial for selecting the best treatment options. Early-stage cancer typically features tumors only in the lung or nearby organs, and it may generally be treated with surgery or radiation therapy. In contrast, advanced lung cancer is often marked by metastasis, which occurs when lung cancer spreads from the original location in the lung to other parts of the body, such as the lymph nodes. Chemotherapy or immunotherapy is generally required for such advanced disease.

CT scans are also used during follow-up care to determine whether treatment was successful at eliminating or shrinking the lung cancer tumor.

Lung Cancer on PET Scans

Positron emission tomography (PET) scans use a mildly radioactive substance to image how organs in the body are functioning, rather than just the structures. Tissues with high metabolic activity will appear as a bright color (yellow to red). Cancer cells have high metabolic activity and can be visualized in contrast to normal cells, which will more likely appear blue to green.

In addition to the primary lung tumor, a PET scan can identify cancer cells scattered throughout other tissues in the body, which is an indicator of metastasis. PET may be used together with a CT scan to aid in diagnosis and staging.

Lung Cancer on Bone Scans

Although not used as often as PET scans, bone scans use radioactivity to specifically detect problems in the bone. If cancer has spread to the bone, the cancer cells will appear as a dark region against a mostly translucent image of the skeleton.

Lung Cancer on MRI Scans

As opposed to X-rays, magnetic resonance imaging (MRI) uses radio waves and magnets to generate detailed images of tissues. As with CT scans, areas with dense tumor tissue appear as a lighter gray relative to normal tissues. An MRI is more commonly used in cases where the cancer metastasizes to the brain or spinal cord.

Lung Cancer Through Bronchoscopy

A bronchoscopy involves inserting a thin tube into the mouth or nose and down into the lungs. The tube has a light and a camera that allows a doctor to view lung tissue in real time and confirm the presence of a tumor.

Lung Cancer Through Mediastinoscopy

A mediastinoscopy allows for real-time visualization of the mediastinum. This procedure involves using a tool similar tool to that of a bronchoscopy. It’s useful for identifying affected lymph nodes in the mediastinum that can be biopsied to aid in the diagnosis of lung cancer.

Talk With Others Who Understand

MyLungCancerTeam is the social network for people with lung cancer and their loved ones. Members come together to ask questions, give advice, and share their stories with others who understand life with lung cancer.

Have you or a loved one been diagnosed with lung cancer? Share your experience in the comments below, or start a conversation by posting on your Activities page.