Please remember that this is general information and is meant as a guide. All diagnoses and treatment options should be discussed in full with a qualified clinician.
Tumours of the pituitary arise from the anterior portion of the gland and are virtually always benign. The pituitary gland secretes a number of different hormones that control other glands in the body. Pituitary adenomas (tumours) are either “functioning” or “non-functioning”. Functioning tumours produce hormones and are named after the hormone involved. The presenting symptoms are usually the result of overproduction of these hormones. The table below shows the three most common hormones involved and their presenting symptoms due to hormone overproduction.
|
Hormone |
Hormone Function |
Presenting Symptom |
|
Growth Hormone |
Controls growth |
Acromegaly: the enlargement of soft tissue cartilage and bones in the face, hands and feet. |
|
Prolactin |
Controls milk production after birth |
Features include: Discharge from breasts, irregular menstrual cycle and infertility. |
|
ACTH |
Controls cortisol production by the adrenal glands. Cortisol helps the body control blood pressure, circulation, sugar levels and stress |
Cushing’s syndrome: Features include behavioural changes, face tends to be rounder, weight gain around the trunk (central obesity) and bruising. |
Other presenting symptoms may include headache, and visual defects. These symptoms are due to local enlargement of the pituitary.
Drugs can sometimes be used to reduce abnormal levels of circulating hormones or to inhibit hormone production. Both of these approaches can cause some tumour shrinkage. Drugs tend to be used in cases where contraindications to surgery exist.
In most cases management is primarily by surgery, which has a high success rate in relieving both local and hormone symptoms. However, following surgery, there is a significant recurrence rate that can be reduced by postoperative radiotherapy.
Radiotherapy can also be used alone as a primary treatment but tends to reduce the normal function of the gland over a 5-10 year period following treatment. Most of these patients will eventually require drug therapy for hypopituitarism.
Radiosurgery is not currently used as primary therapy but tends to be used when treating tumours which have recurred following conventional surgery and/or radiotherapy. It has been shown to be at least as effective as conventional radiotherapy in treating these recurrences, whilst reducing complications such as damage to the optic apparatus, and possibly sparing the remainder of pituitary function. Furthermore, precise calculation of the dose to the optic chiasm and brainstem ensures acceptable limits are not exceeded, even where previous radiotherapy has been given as primary treatment.
Gamma knife treatment has produced excellent results for these pituitary tumours which have proved recalcitrant to initial treatment methods.