Q: I have just been told I have a tumour; does this mean I have cancer?
A: The word ‘tumour’ covers a lot of different conditions and may often have frightening connotations. The vast majority of pituitary tumours are benign: only very rarely (less than 1%) the tumour will be malignant (cancerous). Pituitary tumours are often known as ‘adenomas’; this means a benign (non-cancerous) tumour involving glandular material. With an adenoma, cells of the pituitary gland begin to function independently of the normal control by the brain, and slowly increase in number. Adenomas account for more than 95% of all pituitary tumours.
Q: Why did I get a pituitary tumour?
A: We do not know what causes the majority of pituitary adenomas, but they are not caused by stress. Only in very exceptional cases, less than 1%, are they hereditary. The other 5% of pituitary tumours have many causes. The most common in a very long list are meningioma and craniopharyngioma. All of these tend to cause similar symptoms to pituitary adenomas, although there are some subtle differences. There are several different types of pituitary tumours.
Q: Do tumours vary in size?
A: When pituitary tumours are very small, (less then 1cm), they are called microadenomas. Large tumours, (over 1cm), are called macroadenomas. Large tumours can also prevent normal hormone secretion by other parts of the pituitary gland causing symptoms of hormone deficiency.
Q: I didn’t know I had a tumour, as I had no symptoms – will I still need treatment?
A: Pituitary tumours are sometimes discovered when a patient has a scan for some other reason.This is happening more and more commonly as patients receive scans for other conditions. For example a CT scan or an MRI scan may be performed to investigate headaches, dizziness, and hearing loss or other symptoms and this may lead to discovery of a pituitary tumour which is completely unrelated to these symptoms. Patients with incidentally discovered tumours require surgery only if the tumour has reached a certain size or if it is found to increase in size over time.