LAM Diagnosis


Your doctor diagnoses LAM based on your medical history and the results from diagnostic tests and procedures. You may also see a pulmonologist (a doctor specializing in lung diseases and conditions), who also has experience providing care to people who have LAM.

Medical history

Your doctor will ask you about your medical history to see whether you have symptoms of LAM. Your doctor may ask how long you have had symptoms and whether your symptoms have become worse over time.

Diagnostic tests

Your doctor may order tests to measure how your lung tissue is working and show whether your lungs are delivering enough oxygen to your blood.

Chest X-ray

A chest X-ray is a fast and painless imaging test to look at the structures in and around your chest.

A chest X-ray may look normal in the early stages of LAM. As the disease gets worse, the X-rays may be used to detect cysts in your lungs and monitor any changes over time. Your doctor may use a chest X-ray to look for complications of LAM, such as air in the chest that collapses your lung (a pneumothorax) or fluid in your chest.

The test may be done in the doctor’s office, clinic, or hospital. You will stand, sit, or lie still for the test. Chest X-rays have few risks. The amount of radiation used in a chest X-ray is very small. Talk to your provider if you are or could be pregnant.

Chest CT scan

A chest computed tomography (CT) scan is a painless imaging test that takes many detailed pictures, called slices, of your lungs and the inside of your chest. Computers can combine these pictures to create three-dimensional (3D) models that show the size, shape, and position of your lungs and structures in your chest. 

A chest CT scan can help figure out the cause of lung symptoms such as shortness of breath or chest pain. It can also tell your doctor if you have certain lung problems such as a tumor, excess fluid around the lungs that is known as pleural effusion, or pneumonia.

Your chest CT scan may be done in a medical imaging facility or hospital. You will lie still on a table and the table will slide into the scanner. You will hear soft buzzing or clicking sounds when you are inside the scanner and the scanner is taking pictures. You will be able to hear from and talk to the technician performing the test while you are inside the scanner. For some diagnoses, a contrast dye, often iodine-based, may be injected into a vein in your arm before the imaging test. 

In rare instances, some people have an allergic reaction to contrast dye. There is also a slight risk of cancer, particularly in growing children, because the test uses radiation. Although the amount of radiation from one test is usually less than the amount of radiation you are naturally exposed to over three years, patients should not receive more CT scans than what is recommended by clinical guidelines recommend. 

Lung function tests

Lung function tests can help your doctor see how well your lungs are working. They may help diagnose certain lung conditions or diseases.

Blood tests

Your doctor may order blood tests, such as a test for vascular endothelial growth factor D (VEGF-D) that looks for increased VEGF-D levels in your blood. Higher levels of VEGF-D can stimulate the growth of new blood vessels, which can cause tumors to spread.


Your doctor may also recommend other diagnostic tests, such as a lung biopsy, if other tests are inconclusive.

  • A lung biopsy removes part of your lung to check for LAM cells. Your doctor may do an open lung biopsy, which involves making a cut in your chest wall between your ribs. With a transbronchial biopsy, your doctor inserts a long tube down your windpipe and into your lungs. Your doctor can also diagnose LAM using results from biopsies of other tissues such as the lymph nodes.
  • Video-assisted thoracoscopic surgery (VATS) may be done if your doctor suspects LAM but is not able to diagnose you with a lung biopsy. In this procedure, your doctor makes several small cuts in your chest wall and inserts a small, lighted tube with tools and a camera on the end. The camera takes pictures of the lungs to guide your doctor as they do the biopsy.

Tests for other medical conditions

Your doctor may need to order other diagnostic tests to determine whether you have a related condition called tuberous sclerosis complex (TSC), which can lead to LAM, or to rule out another condition.

  • CT scans or magnetic resonance imaging (MRI) scans of your head can help your doctor determine whether you have TSC. People with TSC often have tumors in the brain and other parts of the body.
  • Genetic testing identifies mutations (changes) in your TSC1 and TSC2 genes to help your doctor confirm that you have LAM and not another lung disease.
  • Thoracentesis uses a needle to collect fluid samples from the lining of your lungs. If your chest imaging tests show that you have fluid building up in the space between the lung and the chest wall (called pleural effusions), your doctor may order a pleural fluid analysis. For this test, a sample is taken from the pleural space.
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