Lymphangioleiomyomatosis (LAM) is a rare lung disease that was first described in the medical literature by von Stossel in 1937.

The disease is characterised by an unusual type of muscle cell that invades the tissue of the lungs, including the airways, and blood and lymph vessels. Over time these muscle cells form into bundles and grow into the walls of the airways, and blood and lymph vessels, causing them to become obstructed.

Although these cells are not considered cancerous, they grow without the usual controls within the lungs. Over time, the muscle cells block the flow of air, blood and lymph vessels to and from the lungs, preventing the lungs from providing oxygen to the rest of the body.

LAM is a disease which affects only women, usually between the onset of puberty and menopause. As delivery of oxygen to the body is progressively impaired, it results in the need for oxygen therapy and as a last resort, lung transplantation.

Symptoms include shortness of breath, cough, lung collapse and chest pain. Because these symptoms are similar to other lung diseases, such as asthma and emphysema, and because LAM is so rare, its diagnosis can be difficult. There are however several tests that physicians can use to confirm the existence of LAM. A high-resolution CT scan and/or a lung biopsy offer the best chance of an accurate diagnosis.

The cause of LAM is unknown, but new studies are underway. Treatments vary in effectiveness from patient to patient, but there have been some examples of the progress of this disease being slowed.

An unusual, frequently asymptomatic, kidney tumour called Angiomyolipoma is found in up to 60% of patients with LAM.