|55 Kenosia Avenue
Danbury, CT 06810
Toll Free: 1.800.999.6673
The National Organization for Rare Disorders (NORD) web site, its databases, and the contents thereof are copyrighted by NORD. No part of the NORD web site, databases, or the contents may be copied in any way, including but not limited to the following: electronically downloading, storing in a retrieval system, or redistributing for any commercial purposes without the express written permission of NORD. Permission is hereby granted to print one hard copy of the information on an individual disease for your personal use, provided that such content is in no way modified, and the credit for the source (NORD) and NORD’s copyright notice are included on the printed copy. Any other electronic reproduction or other printed versions is strictly prohibited.
The information in NORD’s Rare Disease Database is for educational purposes only. It should never be used for diagnostic or treatment purposes. If you have questions regarding a medical condition, always seek the advice of your physician or other qualified health professional. NORD’s reports provide a brief overview of rare diseases. For more specific information, we encourage you to contact your personal physician or the agencies listed as “Resources” on this report.
Copyright 1987, 1989, 1995, 1996, 1998, 2005, 2009
NORD is very grateful to the members of the Scientific Advisory Board of the LAM Foundation for assistance in the preparation of this report and Joel Moss, MD, PhD at the National Heart, Lung, and Blood Insitute, National Institutes of Health, for reviewing this report.
Lymphangioleiomyomatosis (LAM) is a rare progressive multisystem disorder that predominantly affects women of childbearing age. It occurs in women who have tuberous sclerosis, and also in women who do not have a heritable genetic disorder. LAM is characterized by the spread and uncontrolled growth (proliferation) of specialized cells (smooth muscle-like LAM cells) in certain organs of the body, especially the lungs, kidney and lymphatics. Common symptoms associated with LAM include coughing and/or difficulty breathing (dyspnea), especially following periods of exercise or exertion. Affected individuals may also experience complications including collapse of a lung or fluid accumulation around the lungs (pleural effusion). The disorder is progressive and, in some cases, may result in chronic respiratory failure.
The symptoms of LAM vary from case to case. Specific symptoms depend upon which organs are affected by the LAM cells. In most cases, the initial symptoms involve the lung and include shortness of breath, especially upon exercise or exertion. Affected individuals may also experience episodes of chest pain, coughing, wheezing, and coughing up small amounts of blood (hemoptysis).
Some individuals may experience fluid (e.g. chyle) accumulation in the chest cavity around the lungs (pleural effusion). Chyle is a fat-laden cloudy fluid that is absorbed during digestion by the lymphatic vessels located around the intestine. Chyle normally flows through lymphatic vessels into the upper chest (thoracic duct) and is then deposited into veins, where it mixes with blood. In some people with LAM, the lymphatic vessels may rupture or become blocked (obstructed), causing chyle to accumulate in the chest cavity (chylothorax). In some cases, chyle may accumulate in the abdomen causing an increase in girth, a condition called chylous ascites. Involvement of the axial lympatics may also lead to formation fo lymphangioleiomyomas, chyle- filled lymphatic structures within the chest and abdomen.
Some individuals with LAM may experience collapse of a lung that is unrelated to trauma (spontaneous pneumothorax). The symptoms of a collapsed lung may include sudden, sharp chest pain; difficult, rapid breathing; rapid heartbeat (tachycardia); low blood pressure (hypotension); profuse sweating (diaphoresis); dizziness; and/or lack of normal chest movement on the affected side of the chest. A collapsed lung may recur in some individuals.
Approximately 50 percent of individuals with LAM develop angiomyolipomas, which are benign tumors made up of fat, blood vessels and smooth muscle like cells. These tumors affect the kidneys or abdomen and often do not cause symptoms (asymptomatic). In some cases, they may cause flank pain, blood in the urine (hematuria) or bleeding into the abdomen (abdominal hemorrhaging).
Symptoms of LAM may become progressively worse as LAM cell proliferation continues, eventually resulting in chronic life-threatening respiratory failure. The symptoms of LAM often worsen during pregnancy. Many cases of LAM are associated with osteoporosis, a condition characterized by progressive thinning of the bones.
The exact cause of LAM is not known. Since the disease occurs almost exclusively in females of reproductive age, it is possible that an association exists between female hormones (i.e., estrogen and progesterone) and LAM.
Some researchers are studying the connection between a rare genetic disorder known as tuberous sclerosis complex (TSC) and LAM. Approximately 30 percent of women with TSC show evidence of pulmonary lymphangioleiomyomatosis, suggesting that these disorders may share a common cause or origin. TSC is caused by mutations in one of two genes known as the TSC1 gene or TSC2 gene.
Recently, studies have shown that some individuals with LAM who do not have TSC have somatic mutations (e.g., mutations that occur in peripheral tissues after conception) in the TSC2 gene. These mutations were not found in the blood or the normal lung or normal kidney cells of affected individuals. These data suggest that TSC mutations are a cause of LAM even in women who do not have the heritable disorder, TSC.
The symptoms associated with LAM occur due to the spread and accumulation (proliferation) of LAM cells into various organs of the body, especially the lungs. This abnormal proliferation results in the formation of cysts as well as the obstruction of affected airways (breathing tubes), blood vessels, and lymph vessels. Infiltration of the lung with LAM cells may result in progressive breathing difficulties, lung collapse, and interference with the lung's ability to deliver oxygen to the rest of the body.
Obstruction of blood vessels may result in bleeding in the lungs (pulmonary hemorrhage) and coughing up of blood (hemoptysis). Obstruction of lymph vessels may result in chylous effusions and ascites. Lymph vessels are part of the lymphatic system, a circulatory network of vessels, ducts, and nodes that filter and distribute lymph and blood cells throughout the body. Lymph is a fluid that circulates through the body cleaning and strengthening tissue. After performing its functions, lymph is drained away through the lymphatic system.
LAM is a rare disorder that predominantly affects women of childbearing age. The average age of affected individuals at symptom onset is 33. More than 400 cases have been reported in the United States in the medical literature since Dr. Von Stossel first described the disorder in 1937. Some estimates suggest that more than 1,000 women in the United States may have LAM. Many researchers believe that the disorder in under-diagnosed, making it difficult to determine its true frequency in the general population. The Tuberous Sclerosis Association recommends that women with tuberous sclerosis should be screened for LAM at least once on reaching maturity.
Symptoms of the following disorders can be similar to those of LAM. Comparisons may be useful for a differential diagnosis:
There are several obstructive lung diseases that can cause symptoms that are similar to LAM. However, these diseases, such as emphysema, asthma, and chronic obstructive bronchitis, can be ruled out with laboratory tests and radiographic (x-ray) studies.
Tuberous sclerosis is a rare genetic multisystem disorder that is typically apparent shortly after birth but may present in adulthood. The disorder may be characterized by episodes of uncontrolled electrical activity in the brain (seizures); mental retardation; distinctive skin abnormalities (lesions); and benign (noncancerous), tumor-like nodules (hamartomas) of the brain, certain regions of the eyes (e.g., retinas), the heart, the kidneys, the lungs, or other tissues or organs. In addition, many affected individuals may have cyst-like areas within certain skeletal regions, particularly bones of the fingers and toes (phalanges). Characteristic skin lesions include sharply defined areas of decreased skin coloration (hypopigmentation) that may develop during infancy and relatively small reddish nodules that may appear on the cheeks and nose beginning at approximately age four. These reddish lesions eventually enlarge, blend together (coalesce), and develop a wart-like appearance (sebaceous adenomas). Additional skin lesions may also develop, including flat, "coffee-colored" areas of increased skin pigmentation (café-au-lait spots); benign, fibrous nodules (fibromas) arising around or beneath the nails; or rough, elevated, "knobby" lesions (shagreen patches) on the lower back. Approximately 30 percent of individuals with tuberous sclerosis develop pulmonary lymphangioleiomyomatosis. Tuberous sclerosis results from changes (mutations) in a gene or genes that may occur spontaneously (sporadically) for unknown reasons or be inherited as an autosomal dominant trait. Most cases represent new (sporadic) gene mutations, with no family history of the disease. (For more information on this disorder, choose "tuberous sclerosis" as your search term in the Rare Disease Database.)
Langerhans cell histiocytosis (LCH) is a rare spectrum of disorders characterized by overproduction (proliferation) and accumulation of a specific type of white blood cell (histiocyte) in the various tissues and organs of the body (lesions). The appearance of LCH in the lungs may have similarities to LAM on CT scans. (For more information on this disorder, choose "Langerhans cell histiocytosis" as your search term in the Rare Disease Database.)
The diagnosis of LAM may be confirmed by a thorough clinical evaluation that includes a detailed patient history and a variety of specialized tests including radiographic (x-ray) studies, lung function tests, and/or surgical removal and microscopic study of affected tissue (biopsy). In about 80 percent of people with LAM, CT studies reveal cysts in the lungs in or around one or both lungs (pleural effusion). CT studies of the abdomen may reveal angiomyolipomas or lymphangioleiomyomas that support a diagnosis of LAM.
Surgical open lung biopsy is one definitive way to confirm the diagnosis of LAM. These biopsy tissue samples verify the presence of LAM cells.
The treatment of LAM is directed toward the specific symptoms that are apparent in each individual. Fluid accumulation in the lungs (pleural effusion) may be drained by means of a surgically implanted shunt or tube. The surgical insertion of a sterile irritant (such as the antibiotic oxycycline) into the space surrounding the lungs can help to fuse the lung to the chest wall and reduce fluid accumulation around the lungs. Drugs that temporarily widen the bronchial tubes (bronchodilators) may help to alleviate breathing difficulties (asthma-like symptoms) in some cases. Supplemental oxygen should be administered as needed.
Because LAM occurs most often in young women of childbearing age, researchers have speculated that female hormones such as estrogen play a role in the development of the disorder. A link between LAM and female hormones has not been proven. However, many physicians have explored the use of agents that lower the production or effects of estrogen in the body. The results have varied greatly among individuals. Such agents may include medroxyprogesterone acetate. Some affected individuals have experienced symptomatic improvement while on this medication, especially those with recurrent chylous lung effusions, but routine use is not recommended because of significiant side effects. Estrogen-containing medications and dietary supplements should be discontinued in patients with LAM.
A fat replacement diet may or may not be beneficial for some women with chylothorax associated with LAM. Surgical removal of abdominal angiomyolipomas may be necessary in cases where these growths cause bleeding and pain. The initial recommendation is for the angiomyolipoma to be embolized, a procedure that may lead to necrosis of the lesion.
In individuals with severe cases of LAM, lung transplantation may be considered as a last resort. Other treatment is symptomatic and supportive.
Because of the frequent association of LAM with osteoporosis, affected individuals should have their bone mineral density tested. Any loss of bone mineral density should be treated with vitamin D and calcium supplementation and bisphosphonates.
Scientists are investigating the role of hormone therapy in the development and onset of LAM. Some researchers have suggested that hormonal response markers (i.e., estrogen and progesterone receptor status) should be measured in lung tissue biopsy samples. It is hoped that, at some point, these studies may help to determine the best course of treatment. Hereditary factors are also being studied to help determine whether or not a genetic predisposition is essential to the development of LAM.
The drug sirolimus (also known as rapamycin) is currently being explored in patients with advanced diseases as a potential treatment for LAM.
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. Government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
For information about clinical trials sponsored by private sources, contact:
Please note that some of these organizations may provide information concerning certain conditions potentially associated with this disorder.
1301 Pennsylvania Ave NW
Washington, DC 20004 USA
Phone #: 202-785-3355
800 #: 800-586-4872
Home page: http://www.lungusa.org
73-75 Goswell Road
London, EC1V 7ER United Kingdom
Phone #: 020-768-85555
800 #: 030-000-30555
Home page: http://www.lunguk.org
PO Box 8126
Gaithersburg, MD 20898-8126
Phone #: 301-251-4925
800 #: 888-205-2311
Home page: http://rarediseases.info.nih.gov/GARD/
1909 Capitol Avenue,
Sacramento, CA 95811
Phone #: 617-460-7339
800 #: N/A
Home page: www.LAMHealthProject.org
7475 Wisconsin Ave
Bethesda, MD 20814
Phone #: N/A
800 #: N/A
Home page: http://www.lmiresearch.org
PO Box 241956
Los Angeles, CA 90024
Phone #: 310-264-0826
800 #: N/A
Home page: http://www.madisonsfoundation.org
P.O. Box 30105
Bethesda, MD 20892-0105
Phone #: 301-592-8573
800 #: --
Home page: http://www.nhlbi.nih.gov/
P.O. Box 1657
Wimberley, TX 78676-1657 USA
Phone #: 512-847-9303
800 #: 888-855-9463
Home page: http://www.2ndwind.org
4015 Executive Park Drive, Suite 320
Cincinnati, OH 45241 USA
Phone #: 513-777-6889
800 #: 877-287-3526
Home page: http://www.thelamfoundation.org/
Kristof AS, Moss J. Lymphangioleiomyomatosis. In: NORD Guide to Rare Disorders. Lippincott Williams & Wilkins. Philadelphia, PA. 2003:395-6.
Bennett JC, Plum F., eds. Cecil Textbook of Medicine. 20th ed. Philadelphia, PA: W.B. Saunders Co; 1996:1464.
Fishman AP., ed. Pulmonary Diseases and Disorders, 2nd ed. New York, NY: McGraw-Hill Book Company; 1988:965-9.
McCormack FX, Sullivan EJ. Lymphangioleiomyomatosis. In: Murray and Nadel's Textbook of Respiratory Medicine, Fourth Edition. Mason RJ, et al., eds. Elsevier Inc., 2005.
Taviera-DaSilva AM, Stylianou MP, Hedin CJ, Hathaway O, Moss J. Bone mineral density in lymphangioleiomyomatosis. Am J Respir Crit Care Med. 2005;171:61-7.
Khalife WI, Mahmoud F, Larson E, Hardie R. Pulmonary lymphangioleiomyomatosis in a postmenopausal woman: case report and review of literature. S D J Med. 2005;58:139-43.
Bearz A, Rupolo M, Canzonieri V, et al., Lymphangioleiomyomatosis: a case report and review of the literature. Tumori. 2004;90:528-31.
Taviera-DaSilva AM, Stylianou MP, Hedin CJ, Hathaway O, Moss J. Decline in lung function in patients with lymphangioleiomyomatosis treated with or without progesterone. Chest. 2004;126:1867-74.
Crooks DM, Pacheco-Rodriguez G, DeCastro RM, et al., Molecular and genetic analysis of disseminated neoplastic cells in lymphangioleiomyomatosis. Proc Natl Acad Sci USA. 2004;101:17462-7.
Johnson SR, Whale CI, Hubbard RB, Lewis SA, Tattersfield AE. Survival and disease progression in UK patients with lymphangioleiomyomatosis. Thorax. 2004;59:800-3.
Sato T, Seyama K, Kumasaka T, et al., A patient with TSC1 germline mutation whose clinical phenotype was limited to lymphangioleiomyomatosis. J Intern Med. 2004;256:166-73.
Pechet TT, Meyers BF, Guthrie TJ, et al., Lung transplantation for lymphangioleiomyomatosis. J Heart Lung Transplant. 2004;23:301-8.
Finlay G. The LAM cell: what is it, where does it come from, and why does it grow? Am J Physiol Lung Cell Mol Physiol. 2004;286:L690-3
Carsillo T, Astrinidis A, Henske EP. Mutations in the tuberous sclerosis complex gene TSC2 are a cause of sporadic pulmonary lymphangioleiomyomatosis. Proc Natl Acad Sci USA 2000;97:6085-90.
Urban T, Lazor R, Lacronique J, et al., Pulmonary lymphangioleiomyomatosis. A study of 69 patients. Medicine (Baltimore). 1999;78:321-37.
Smolarek TA, Wessner LL, McCormack FX, Mylet JC, Menon AG, Henske EP. Evidence that lymphangioleiomyomatosis is caused by TSC2 mutations: chromosome 16p13 loss of heterozygosity in angiomyolipomas and lymph nodes from women with lymphangioleiomyomatosis. Am J Hum Genet. 1998;62:810-5.
FROM THE INTERNET
McKusick VA., ed. Online Mendelian Inheritance in Man (OMIM). Baltimore. MD: The Johns Hopkins University; Entry No:606690; Last Update:11/05/2003. Available at: http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=606690 Accessed On: June 15, 2005.
Islam A. Lymphangioleiomyomatosis. eMedicine Journal. 2004;3:11pp. Available at: http://www.emedicine.com/radio/topic415.htm Accessed On: June 15, 2005.
Kelly J. Lymphangioleiomyomatosis. eMedicine Journal. 2004;3:11pp. Available at: http://www.emedicine.com/med/topic1348.htm Accessed On: June 15, 2005.
Young LY, McCormack FX. Pulmonary and Critical Care Update. 2004; Progress in Lymphangioleiomyomatosis. Accessed on July 9, 2005.
Report last updated: 2009/05/05 00:00:00 GMT+0