Medicines for Pituitary adenoma

What it is

A pituitary adenoma is a growth (tumour) on the pituitary gland — a pea-sized gland at the base of the brain that acts as the "master gland", controlling many of the body's hormones. The great majority of pituitary adenomas are benign (non-cancerous) and slow-growing, and they are common. They cause problems in two main ways, depending on the type. Some are "functioning" adenomas, which produce excess amounts of a particular hormone — for example, too much prolactin (a prolactinoma, causing effects such as milk production, and menstrual or fertility problems, or reduced libido), growth hormone (causing acromegaly), or the hormone that drives cortisol (causing Cushing's disease). Others are "non-functioning" adenomas, which do not produce excess hormone but can cause problems by their size — pressing on the normal pituitary gland (reducing its hormone production, causing hypopituitarism), or on the nearby optic nerves (affecting vision, classically the outer parts of the visual fields), or causing headaches. Many small adenomas cause no symptoms and are found incidentally on a brain scan done for another reason. Because pituitary adenomas can affect hormones and nearby structures, they are assessed and managed by specialists, and, importantly, most are very treatable.

How it is treated

Pituitary adenomas are managed by endocrine specialists, often with input from pituitary surgeons and eye specialists, and the approach depends on the type of adenoma, its size, whether it produces excess hormone, and whether it affects the pituitary function or vision. Assessment includes hormone blood tests (to check for excess hormones and for any underactive pituitary function), a detailed pituitary MRI scan, and, where the adenoma is near the optic nerves, tests of the visual fields. Treatment is tailored: for a prolactinoma (the commonest functioning type), the first-line treatment is usually medicine (dopamine agonist tablets), which is highly effective at reducing prolactin and shrinking the tumour, often avoiding surgery. For other functioning adenomas (such as those causing acromegaly or Cushing's disease) and for non-functioning adenomas that are large or affecting vision or pituitary function, surgery (usually a minimally invasive operation through the nose to remove the adenoma) is often the main treatment, sometimes with medicines or radiotherapy in addition. Small, non-functioning adenomas causing no problems may simply be monitored with periodic scans and hormone checks. Any underactive pituitary hormones are replaced. Regular long-term follow-up is important. The reassuring message is that most pituitary adenomas are benign and very treatable — with medicines (particularly effective for prolactinomas), surgery, or monitoring, tailored to the individual — so that hormone problems and any pressure on nearby structures can be well managed.