Phaeochromocytoma

Phaeochromocytoma.
I've watch the 2nd season of House M.D,story bout the very,very clever doctor.The diagnosis this time is Phaeochromocytoma.So i've read bout it so lets see wat is it actually.

It is the condition where body are producing too much of adrenalin.


Causes/ Aetiology
1.Tumor in the unner part of adrenal galand specifically call adrenal medulla. This cause overproduction of adrenalin and noradrenalin. Comprise 90 % of causes.
2.About 10 % are from - ganglioneuroma or symphatoblastoma
it is due to over production from the symphatetic nerve chain and ganglions which swells.So it produce too much of adrenalin.

Malignant?
90% are benign
10% are found in bith adrenal glanb but still benign
10% are malignant and can spread around body

Familial Association
10% runs in families where other family members have a same condition
Two major famili association:
1. Those with neurofibromatosis,
2.In Multiple Endocrine Neoplasia (MEN type 2)

Sign And Symptom
1. Anxienty
2. Headache
3. sweating
4. Palpitation
5. Tremor

Often the patients describe sudden onset of attacks with thumping severe headache, profuse sweating and yet look pale, fast heart palpitations, extreme anxiety as if about to die, body tremor, and if measured, a very high blood pressure. After some time (usually less than 15mins but in 80% as long as one hour) the attack subsides and the patient feels washed out. The frequency of attacks can vary from once every 2 months to many times per day but usually become more frequent as time goes by. Between attacks, blood pressure may remain raised but in some reverts to normal. Some 50% of patients exhibit a postural fall in blood pressure even if the supine pressure is normal. The severity of the crises are not dependent on the size of the tumour but on its overactivity; small tumours can be very overactive.

Investigation
1. High levels of noradrenaline and/or adrenaline in a 24hour collection of urine.
2. Occasionally blood noradrenaline and/or adrenaline are measured but usually this is not required where urine tests show high levels of these hormones.
3. CAT scan or MRI scan of adrenals show one or both adrenals enlarged. Where the condition is due to sympathetic chain tumour a MRI of the body will pick up the abnormalities.
4. Radioactive labelled meta-iodobenzyl guanidine (MIBG) scan. MIBG is taken up by the cells overactively making noradrenaline / adrenaline. This test is not always successful if the cells concerned are not actually overproducing at the time of the testing.

Treatment
The aim is to surgically remove the tumour(s). However it is essential to first block the action of the excess noradrenaline / adrenaline before the operation. The reason for this is that just the anaesthetic and later handling of the tumour at the time of operation can precipitate a crisis. In a crisis the tumour releases massive amount of hormone resulting in a dangerously high level of blood pressure which could cause a heart attack or brain haemorrhage.To reduce this risk the endocrinologist will arrange for the patient to have the action of noradrenaline / adrenaline blocked by a special drug called phenoxybenzamine. His drug is usually begun in hospital for as it begins to work blood pressure can precipitiously fall requiring expansion of blood volume with salt water given intravenously. The drug dosage will be gradually increased until maximum effect is achieved and this can take many days. For acute attacks the doctor has available an intravenous preparation called phentolamine but this doesn’t last long hence the need for the long acting phenoxybenzamine. Once the latter is fully effective then the specialist will add another drug called a beta blocker (usually propanolol) to reduce the force of heart beat and prevent any fast palpitation.


Type of Operation
The operation is called an adrenalectomy. This may be of a key hole type but the surgeon may need to do a conventional approach. The latter may involve an incision in your back just below your ribs on one side. If both adrenals have to be removed then this is often done by an incision across the front of the upper abdomen.