Lymphangioleiomyomatosis (lim-FAN-jee-o-LYE-o-MY-o-ma-TOE-sis) is a rare, fatal, multi-system disease affecting women in their childbearing years. LAM causes destruction throughout the body, often in the lungs, kidneys and lymphatics. This destruction is attributed to migration, clustering, cell signaling and cell-other cell-cell “LAM cell” abnormalities. Over time, patients may progress to respiratory failure as cysts and nodules take over normal lung. There is no known cure or treatment, and the mechanisms of destruction of lung and other tissues in LAM are poorly understood. One gene defect (TSC2) has been identified in lung tissue, kidney lesions (i.e., angiomyolipomas or AMLs) and circulating cells. Work to identify other mutations and modifier genes is now underway.
Early symptoms of LAM may include shortness of breath, collapsed lung(s), chest pain, abdominal discomfort, and frequent coughing. Over time, women with LAM may experience complications due to leaky lymphatics (chylous or pleural effusions), become less active and require supplemental oxygen full time. Not only is LAM commonly mis-diagnosed as asthma, emphysema or bronchitis, it is also under-diagnosed, as a LAM diagnosis requires a high-resolution CT scan. People with respiratory issues are not routinely scanned due to cost and other factors. There is increasing thought that otherwise healthy, non-smoking women with one or more pneumothoraces (i.e., lung collapses) should have a CT scan to rule out LAM. Progression is variable in LAM. Women with LAM can progress to respiratory failure in less than two years or more than 20 years. We cannot predict who will progress quickly very accurately at this time.
The most common signs and symptoms of LAM include one or more of the following which are likely caused by the uncontrolled growth of LAM cells: dyspnea or shortness of breath, especially following exertion. At first you may feel short of breath only during strenuous activity. Over time, you may have
About 6 of every 7 women with LAM develop a collapsed lung (pneumothorax (noo-mo-THOR-aks)) at some point. Sometimes one lung will collapse over and over again. Both lungs can collapse too. This is a serious condition that can be life threatening. A lung that is only partly collapsed may slowly re-expand without treatment, but treatment is often required.
Other diseases can cause many of these signs and symptoms and
complications, so it is important that you see a doctor.
LAM cells are very similar to cells found in the lungs of patients
with a genetic (inherited) disorder called tuberous sclerosis complex
(TSC). As many as 39 percent of women with TSC also have LAM. In
TSC, tumors grow in the brain, kidneys, heart, eyes, lungs, skin and
When it is not accompanied by LAM, TSC is usually treatable; however, it can have serious effects including seizures, developmental delays, and kidney disease.
Although LAM is not thought to be inherited, TSC and LAM seem to be affected by mutations in one of two tumor suppressor genes, TSC1 (which encodes a protein called hamartin) and TSC2 (encoding a protein called tuberin).
LAM affects women of all races, nations and economic backgrounds. Between 30,000 and 50,000 women worldwide are estimated to have sporadic pulmonary LAM. Approximately 250,000 women worldwide have the form of LAM linked to a genetic disorder called Tuberous Sclerosis Complex (TSC). LAM is understood to be more sex-specific than breast cancer.