Diagnosis of Lymphangioleiomyomatosis (LAM) & Associated Tests
LAM is diagnosed based on signs and symptoms along with the results from tests and procedures.
The signs and symptoms of LAM are often very similar to the signs and symptoms of other respiratory diseases, such as asthma, emphysema, and bronchitis. It is important for your doctor to rule out these conditions before making a diagnosis of LAM.
High resolution CT scan (HRCT) - performed to provide detailed images of the structure of your chest and abdomen. The CT scan of your chest will provide information about the portion of your lungs with cysts caused by LAM. The CT scan of your abdomen will help your doctor determine if you have any growths called angiomyolipomas (AMLs) in your kidneys, other abdominal organs, or lymph nodes.
Pulmonary Function Tests (PFTs) - are one way to measure your lung function and the progression of LAM. Full PFTs include spirometry, lung volume tests and diffusing capacity of the lung for carbon monoxide (DLCO). Spirometry measures the amount and speed of air that you can inhale and exhale. Lung volume tests measure how much air is in your chest. DLCO testing measures how well oxygen passes from the air sacs of your lungs into your blood.
Six minute walk test - involves walking for six minutes while a member of the healthcare team monitors your oxygen saturation (the amount of oxygen in your blood stream), your heart rate, and how far you are able to walk.
Blood tests – include measurements of blood count levels, electrolyte levels, liver and kidney functioning, and clotting ability.
Exercise testing - can provide information about how your heart and lungs respond to the increased demands of exercise.
Results from the above tests can sometimes provide enough information for your doctor to make a diagnosis of LAM. If more information is necessary, your doctor may ask that you have a lung biopsy.
Lung biopsy - a procedure in which a few small pieces of the lung are removed for analyses. There are several methods for obtaining a lung biopsy. Your doctor will discuss the various options with you.