What is it about ?
The pituitary gland is a small gland (0.5 g) housed in a bony cavity located behind the nose at the base of the brain. It is the central link of the entire hormonal system. The pituitary is made up of two areas:
- the anterior lobe or adenohypophysis (“adeno” means gland) produces different hormones that play a role in the function of other glands. They regulate, among other things, the functioning of the thyroid gland, adrenal glands and ovaries.
- the posterior lobe or neurohypophysis is responsible for regulating water and fluids in our body and also produces different hormones that have a direct effect (without the intervention of other glands), such as growth hormone and prolactin, which plays a role during pregnancy and is responsible for the production of milk in the breasts.
Over time, a usually benign tumor (adenoma) can develop in the pituitary gland. Malignant tumors of the pituitary gland are very rare. On the other hand, metastases of malignant tumors can develop in the pituitary gland.
Depending on the location, size and activity of the tumor, various symptoms may appear. Small, inactive tumors usually have no symptoms. Larger tumors (macroadenomas) can cause compression symptoms due to their size and also influence the normal production of hormones (hormone overproduction or deficiency).
What is their frequency?
Pituitary gland tumors are relatively common. They are discovered by chance in 10 to 30% of people who have an x-ray examination of the skull, for example.
How to recognize them?
Hormonal deficiency
Hormone deficiencies often occur in the following order:
- Growth hormone: Symptoms of growth hormone deficiency are slower growth and development, reduction in muscle mass along with muscle weakness, abnormal teeth, reduced bone density. The risk of developing cardiovascular disease is also higher.
- Sex hormones: Symptoms of sex hormone deficiency in men are decreased libido, impotence, little beard, muscle weakness, fatigue and pallor due to anemia. In women, menstruation disorders and even the complete absence of periods can be observed.
- A deficiency in TSH (hormone that stimulates the thyroid) causes hypothyroid (lazy thyroid).
- In case of cortisol or stress hormone deficiency, the symptoms are less marked than in addison’s disease. In particular, a disturbance in the salt level in the blood can be dangerous.
Excessive secretion of hormones
- Too much growth hormones results in exaggerated growth (acromegaly) of the chin, hands and feet.
- Excess cortisol causes Cushing’s syndrome, the symptoms of which include an uncontrollable increase in blood pressure (hypertension), weight gain and a swollen face.
- A pituitary gland tumor that produces too much prolactin is usually called a prolactinoma. It is the most common pituitary tumor. In women, it causes discharge of milk from the breasts, menstruation problems or infertility. In men, it is responsible for a decrease in libido, impotence or infertility.
Optic nerve compression
Compression of the optic nerve by the tumor can lead to reduced field of vision, impaired vision, and paralysis of the eye muscles. It gives the impression of having blinders. Often, symptoms appear slowly, so it often takes a long time for the tumor to be detected.
Other symptoms
Exceptionally, cerebrospinal fluid may flow through the nose. In many cases, there are no symptoms.
How is the diagnosis made?
The discovery of a pituitary gland tumor is often pure coincidence, for example during an x-ray of the skull for another reason. With a detailed blood test, the doctor will notice that some hormone levels are abnormal. A stimulation test may be indicated. It shows that the levels of the hormones in question, despite the stimulation, do not increase sufficiently. You will then have an MRI scan of the base of the skull to confirm the presence of a tumor and to determine its size and influence on the optic nerve.
What can the doctor do?
In Cushing’s syndrome and acromegaly, surgical removal of the tumor is usually indicated. In acromegaly, drugs are usually given in the period before and after the operation. In case of growth hormone deficiency, growth hormones are administered subcutaneously using an injection pen. In some cases, radiation therapy is necessary. A prolactinoma is usually treated with medication.
If the tumor does not cause symptoms, we can wait. Regular monitoring is however recommended.
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