What is LAM?

LAM is a rare disorder that occurs almost exclusively in women and is generally diagnosed in women of childbearing age. LAM mainly affects the lungs, where an abnormal type of cell (called a LAM cell) builds up. This build up of LAM cells occurs around the airways (breathing tubes) and also around the blood vessels and the lymph vessels (lymph vessels drain excess fluid from the lungs). The LAM cells lead to cysts developing in the lung and these may be seen on a chest x-ray and are shown very clearly on a CT lung scan. The main effects of LAM are in the lungs but around half of patients also have tumours in the kidneys; they are not malignant but can cause bleeding. Lymph nodes may also be enlarged, usually in the chest or abdomen, but they don’t normally cause problems.

The name lymphangioleiomyomatosis reflects the different components of the disease. Lymph and angio refer to the lymph and blood vessels that are involved and leiomyo refers to smooth muscle which LAM cells resemble. LAM that occurs on its own is sometimes called sporadic LAM to distinguish it from LAM that occurs in patients who also have tuberous sclerosis.