Lymphangioleiomyomatosis (LAM)

LAM is a rare multisystem disease that affects predominantly women, approximately 3-5 per million but has also found in men and children. LAM is characterized by an abnormal growth of smooth muscle like cells (LAM cells) that invade the lungs, kidneys and lymphatics of the chest, abdomen, and pelvis.

Causes of LAM

LAM is caused by mutations in tuberous sclerosis genes. LAM can be sporadic or occur in patients with an inherited syndrome called tuberous sclerosis complex (TSC). Unregulated growth of LAM cells can result in cystic lung destruction and extrapulmonary tumors (e.g. angiomyolipoma, lymphangioleiomyomas) or accumulation of lymph rich-fluid in the chest and abdomen.

LAM symptoms

  • Shortness of breath
  • Chest pain
  • Chronic cough
  • Pneumothorax (collapsed lung)
  • Pleural effusion or chylothorax which is a milky white fluid consisting of lymph and droplets of fat.
  • Abdominal tumors
    • Lymph-filled cystic mass
    • Kidney tumor (angiomyolipoma)

Diagnosis and tests for LAM

  • High resolution CT scan—this may reveal characteristic cystic structures of LAM
  • Abdominal CT scan or ultrasound—used to evaluate for abdominal or kidney tumors
  • Pulmonary function test to assess the current lung functions and monitor disease progression
  • VEGF-D blood test, a high value can be diagnostic in LAM.
    • Keep in mind that a normal result on this test does not rule out LAM as a diagnosis
  • Lung biopsy—this may be required in patients without confirmatory features from the above investigation

LAM treatment

  • Medicines
    • Sirolimus (known as rapamycin or Rapamune)
    • Everolimus (known as Afinitor)
  • Long-term treatment is recommended for patients with abnormal lung function and evidence of progressive lung function decline. It is also effective in patients with refractory chylous effusions or angiomyolipoma.
    • Bronchodilators
    • Oxygen therapy
    • Pulmonary rehabilitation
    • Lung transplantation
  • Treatment of complications
    • Chest tube drainage and pleurodesis, which is a procedure to close the pleural space in pneumothorax

Support and additional resources for LAM patients

Outlook for people with LAM

LAM is a chronic disease. Some patients remain stable over many years and others decline more rapidly. Treatment is now available. Patients and physicians should make therapy decisions together after discussing all possible options.

When to contact your doctor

Because the disease is rare, patients with LAM or suspected LAM should be evaluated in a specialty center. University of Iowa Health Care is one of the LAM Foundation approved LAM clinics in the United States. Our physicians have the interest and expertise in the care and treatment of patients with LAM.

Last reviewed: 
January 2018
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