Lymphangioleiomyomatosis (lim-FAN-je-o-LI-o-MI-o-ma-TO-sis) is a rare lung disease that usually strikes women during the prime of their lives. Known as LAM for short, this disease is characterized by an abnormal growth of smooth muscle cells, especially in the lungs, lymphatic system and kidneys. Unregulated growth of these cells can lead to loss of lung function, accumulation of lymph rich-fluid in the chest and abdomen and growth of tumors in the kidneys. There are two forms of LAM, Sporadic LAM (S-LAM) and Tuberous Sclerosis LAM (TSC-LAM). S-LAM occurs for unknown reasons. LAM also can occur in women who have a rare disease called tuberous sclerosis complex (TSC).

Although great strides have been made in researching the disease, there is no cure for LAM. However, treatment with the drug sirolimus (also known as rapamycin or Rapamune) as well as everolimus (also known as Afinitor) may improve lung function in some women with LAM. Oxygen therapy is required for women with advanced lung disease. Lung transplantation is often considered for very advanced disease. While many women with LAM add several years to their lives through lung transplantation, it is not a cure.