Lymphangioleiomyomatosis

Progressive lung disease

Lymphangioleiomyomatosis (LAM) is a disorder in which abnormal smooth muscle cells grow rapidly in lung and lymph tissue. What causes LAM is not entirely understood. LAM primarily affects young and middle-aged premenopausal women, but it can occur in men and in other age groups. It is not known how often LAM occurs, but there are more than 1,000 individuals in the LAM Foundation Registry.

Lymphangioleiomyomatosis may be associated with the presence of an underlying disease, especially tuberous sclerosis complex.

Symptoms
Symptoms of LAM depend upon the tissues affected by abnormal smooth muscle cell growth.

• Lungs – shortness of breath (dyspnea), cough, formation of cysts, lung collapse (pneumothorax)
• Lymph system – swollen lymph nodes, formation of cysts; obstruction of the ducts can lead to lymph fluid (chyle) leaking into the chest (chylothorax) or abdomen (chylous ascites)
• Kidneys – non-cancerous tumor-like overgrowth of tissue (angiomyolipoma)

If tuberous sclerosis complex or another disorder is present, there may be additional symptoms such as presence of hamartomas (non-cancerous tumors).

Diagnosis
The respiratory symptoms of lymphangioleiomyomatosis are similar to those of asthma or chronic obstructive pulmonary disease, so the diagnosis of LAM may not be apparent. A chest x-ray may look normal. A high-resolution computed tomography (CT) scan of the chest, however, will show the presence of LAM in lung tissue. Ultrasound or CT scan of the abdomen may reveal the presence of angiomyolipoma.

Tests of lung capacity and airflow (pulmonary function tests) will be abnormal in lymphangioleiomyomatosis. A sample of lung tissue (biopsy) can be taken to look for changes characteristic of LAM. In many individuals, though, a high-resolution CT scan makes biopsy unnecessary. There is no specific blood test for LAM.

Treatment
Treatment of lymphangioleiomyomatosis focuses on treating problems such as pneumothorax or angiomyolipoma. Because LAM most often occurs in premenopausal women, some women with LAM have been treated with progestin in an attempt to reduce the effects of the female hormone estrogen. Respiratory care by a pulmonologist can help relieve shortness of breath. If severe lung disease occurs, lung transplantation may be considered.

For more information about LAM, including support and resources for those affected by the disease, contact the LAM Foundation.

Last updated 3/1/06

Information for this article was taken from:
- Kelly, J. (2004). Lymphangioleiomyomatosis. eMedicine, accessed at http://www.emedicine.com/med/topic1348.htm
- McCormack, F. X. (2006). Lymphangioleiomyomatosis. Medscape, accessed at http://www.medscape.com/viewarticle/518317