Lymphangioleiomyomatosis (LAM)

What Is LAM?

Lymphangioleiomyomatosis, generally known as LAM, is a rare condition which affects a specific form of muscle cell in the lung. LAM affects women and it is estimated that only 60 women in the UK have the disease. The average age of women affected by the disease is 34 and it is very rare among women who have had the menopause.

LAM affects the smooth muscle cells and causes overgrowth of these cells around the lymph vessels, airways and blood vessels, which causes cysts to develop in the lungs. In some cases, growths can also develop in the kidneys and although they are not malignant they may cause bleeding in some cases.

What causes LAM?

The cause of LAM is currently unknown, although experts do know that it is not inherited or passed on to children by their parents. There is a suggestion that LAM may be caused by a chromosomal mutation, which causes overgrowth of smooth muscle cells, but it is not known why this would occur. Research into the cause of LAM is ongoing.

What are the effects of LAM?

LAM affects people in different ways. The most common symptom is breathlessness and most people develop LAM after a pneumothorax (commonly referred to as a collapsed lung). LAM affects the lymph and blood vessels and the smooth muscle. The terms lymph and angio refer to lymph vessels and blood vessels, while leiomyo refers to the smooth muscle.

Other symptoms of LAM include:

  • Coughing up blood.
  • Coughing up sticky, milky phlegm.

LAM can also cause some people to develop fibroids and they may also be prone to inflamed lymph nodes, however, this should not cause any pain.

How is LAM diagnosed?

It can be difficult to diagnose LAM because many of the symptoms are similar to other lung conditions. If you have any of the symptoms listed above and your doctor suspects that you have LAM, they will carry out tests including a chest X-ray and breathing tests. The results will usually give the doctor a good idea of what is happening, but they will probably order a CT scan to confirm the diagnosis and a lung biopsy test may also be carried out. The CT scan will show doctors detailed images of the lung and they will be able to identify any cysts. A biopsy test involves making a tiny incision in the chest and is carried out under general anaesthetic. Kidney tumours can also be detected with a CT scan.

Hormonal changes and LAM

Hormonal changes can affect LAM, especially as the disease tends to develop before the menopause. Oestrogen may speed up the progression of the disease and progesterone can slow it down. Research into the effect of hormonal changes is ongoing but experts have come up with the following information:

  • HRT (hormone replacement therapy): HRT involves oestrogen and can accelerate the disease.
  • Pregnancy: in some women, pregnancy does not affect their condition, but in others it makes it worse. Complications include pneumothorax and pleural effusion.
  • Menopause: the rate the disease progresses usually slows after the menopause.
  • Contraceptive pill: most contraceptive pills contain oestrogen and progesterone and in most cases taking the pill does not affect LAM progression; however, it may be advisable to take a progesterone-only pill.
  • Fertility treatment: fertility treatment usually involves oestrogen, so it is likely that it will cause your condition to deteriorate. Your doctor can discuss your options with you if you decide you want to have fertility treatment.

Treatment for LAM

Currently there is no cure for LAM, however, there are treatments that can help to ease symptoms, treat complications and slow progression of the disease. Treatments include:

  • Treating breathlessness: breathlessness can be caused by pleural effusion and pneumothorax. If this is the case, they will be treated as priority and this should make breathing easier. A pneumothorax can be treated by removing air from the pleural space by inserting a needle into the chest wall, while a pleural effusion is treated by removing trapped fluid from the lungs.
  • Lung transplant: this may be considered if a patient has very severe LAM.
  • Vaccination: patients with LAM are advised to have a flu vaccination every year and a pneumococcal vaccination may also be recommended to reduce the risk of developing pneumonia.
  • Treatment for kidney tumours: small tumours do not usually cause any problems and may not require treatment, while larger tumours are usually removed by surgery.
  • Slowing progression: treatments including progesterone and a medication called Tamoxifen can be used to slow the progression of the disease.

LAM and tuberous sclerosis

LAM and tuberous sclerosis cause similar effects and symptoms but there is an important difference: LAM is not inherited, while tuberous sclerosis is.

Flying with LAM

Flying can increase the risk of pneumothorax and, although in many cases it is safe to fly, you should consult your doctor before you fly.

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