LAM - Diagnosis - Diagnosis

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

Your doctor may order blood tests, breathing tests, and imaging tests to measure how your lung tissue is working, and whether you have LAM. These tests can also show whether your lungs are delivering enough oxygen to your blood. Your doctor may also have you undergo other diagnostic tests, such as a lung biopsy, if other tests are inconclusive.

• Chest X-ray. In the early stages of LAM, your chest X-rays may look normal. 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 a collapsed lung or fluid in your chest.
• High-resolution computed tomography (CT) scan to provide detailed pictures of your lungs and detect lung cysts, excess fluid, a collapsed lung, or lymph nodes that are larger than normal. The test can also show damage to the lungs. High-resolution CT scans of your abdomen and pelvis can show whether you have tumors in your kidneys, other organs in your abdomen, or your lymph nodes.
• Pulmonary function tests to show how well your lungs are working and measure the amount of air you breathe in and out.
• Blood test for vascular endothelial growth factor D (VEGF-D) to look for increased VEGF-D levels in your blood. VEGF-D can be involved in the spread of tumors by stimulating the growth of new blood vessels. VEGF-D levels of 800 pg/mL (picograms per milliliter) or more may suggest a diagnosis of LAM.
• Biopsy of the lungs to check for LAM cells. There are several types of lung biopsy. Open lung biopsy involves making a cut in your chest wall between your ribs. With transbronchial biopsy, your doctor will insert a long tube down your windpipe and into your lungs. Your doctor also can diagnose LAM using the results from biopsies of other tissues such as from the lymph nodes. Video-assisted thoracoscopic surgery (VATS) is often done in lieu of a more invasive open lung surgery that requires a large chest incision, or after transbronchial biopsy that may not definitively diagnose LAM. This surgery does require general anesthesia to make you sleep. Your doctor will insert a small, lighted tube into little cuts made in your chest wall.

Your doctor may need to order other diagnostic tests to determine whether you have TSC or to rule out another condition.

• CT scans or magnetic resonance imaging (MRI) scans of your head to help your doctor determine whether you have TSC. People who have TSC often have tumors in the brain and other parts of the body.
• Genetic testing to identify mutations in your TSC1 and TSC2 genes can help your doctor confirm that you have LAM and not another lung disease.
• Thoracentesis to collect fluid samples from the lining of your lungs. If your chest imaging tests show that you have pleural effusions, your doctor may order a pleural fluid analysis. For this test, a fluid sample is taken from the pleural space, which is a thin space between the two layers of tissue that line the lungs and chest cavity. The fluid is studied for a milky substance called a chylothorax.

• Return to Risk Factors to review family history and genetic factors that increase your risk of developing LAM.
• Return to Signs, Symptoms, and Complications to review common signs and symptoms of LAM.