What are signs or symptoms of LAM?
For many patients with LAM the first sign of the disorder is when they develop a collapsed lung, known as a pneumothorax. This occurs when one of the cysts bursts and air leaks into the space around the lung. A pneumothorax usually causes sudden breathlessness, often with a sharp pain, and it requires treatment in hospital. If the pneumothorax recurs a small operation is usually needed; this will prevent a further pneumothorax though some patients continue to be aware of occasional gurgling in their chest after the operation.
Many symptoms of LAM are similar to those of more common lung diseases such as asthma and for this reason patients may have symptoms for some time before LAM is diagnosed. Symptoms, X-rays and breathing (lung function) tests may suggest LAM but the diagnosis is usually confirmed by a CT scan (a detailed X-ray scan) of the lungs and sometimes with a lung biopsy. In a patient with LAM the CT scan usually shows typical cysts throughout the lungs.
In around one third of cases a lung biopsy may be performed to ensure that the diagnosis is correct. This is usually carried out through a fairly small incision in the chest under a general anaesthetic. With LAM the biopsy will show the typical cysts and LAM cells. The kidney tumours are also seen best on a CT scan although they can also be seen with ultrasound. Patients with kidney tumours or tuberous sclerosis seldom need to have a lung biopsy performed and these features should be looked for before deciding to perform a lung biopsy.
As the LAM cells enlarge there is a fall in lung function but the rate at which this occurs varies markedly between patients. A few patients still have moderately preserved lung function after 20 years whilst others are less fortunate and deteriorate quite rapidly. Most patients are between these extremes. Looking at change in lung function over a period of time gives a good indication of the rate at which the disease is progressing in an individual patient.
Some patients with LAM have a benign tumour in the kidney (called an angiomyolipoma). Most kidney tumours
in LAM are small, do not cause symptoms and do not need treatment as they are benign. Patients with
LAM should have a kidney scan to see if angiomyolipomas are present, and if they are present, they should
be monitored to ensure they are not growing. Occasionally larger tumours cause pain or bleeding and may
need to be treated. This is done either by removing the tumour with an operation or blocking its blood supply
(embolisation) which causes it to shrink. Embolisation is done through a catheter inserted into the artery to the
kidney and it does not normally need a general anaesthetic. Patients recover more quickly from embolisation.
It is not possible to treat all tumours in this way however and the procedure is not performed in all hospitals.
The aim of treatment is to preserve as much normal kidney as possible, and avoid removing a kidney unless
there is no alternative.
Both the lung condition and the kidney tumours seen in LAM can occur in patients with a disease called
tuberous sclerosis. Tuberous sclerosis is generally associated with unusual skin changes, tumours in other
organs and sometimes epilepsy (fits), learning and behavioural problems. There is a very important difference
between tuberous sclerosis and sporadic LAM which is that tuberous sclerosis is inherited whereas LAM is sporadic.