Pituitary Adenoma
What is it?
Pituitary adenoma is a non-cancerous tumour that develops in the brain. This tissue growth, also known as neoplasia, is the result of cell proliferation. It is always benign, that is to say it is non-cancerous. The adenoma gets its name from the fact that it originates from the pituitary gland, a gland located at the base of the brain that controls all of our hormonal secretions.
Types of pituitary adenomas
Pituitary adenomas are classified under different types, depending on:
- their dimensions: if the adenomas are less than 10mm they are named micro-adenomas. Any adenomas equal to or greater than 10mm are called macro-adenomas.
- their "productivity": pituitary adenomas that are secreting (that is to say that they influence hormone production) and non-secreting
Disorders caused by adenomas
Macro-adenomas can cause problems if the tumour mass is too large because it compresses the brain. The brain is then no longer able to secrete enough hormones. Some secretory pituitary adenomas also produce an excess of the pituitary hormone and this causes disorders such as Cushing's disease or hyperprolactinemia.
Symptoms
The symptoms of pituitary adenoma are very varied:
- Compression disorders of the brain, in cases of macro-adenomas, causes symptoms such as headaches and vision problems (blurred vision or loss of peripheral vision), dizziness, pain in the eyes and face, fatigue, nausea, extreme thirst and frequent urination.
- In the case of a prolactin tumour (adenoma that produces the hormone prolactin) causes: endocrine dysfunction, including amenorrhea (interruption of the menstrual cycle in women), production of breast milk without pregnancy or childbirth, breast development in men, loss of libido, erectile dysfunction, increased weight, cardiac arrhythmia, metabolic disorders, osteoporosis, impaired blood sugar, hypertension.
If it is a growth hormone tumour it causes acromegaly (gigantism), joint pain, high sugar level, heavy perspiration, increased hair growth.
- If it is a corticotrophin (ACTH) tumour that makes too much cortisol, Cushing's disease can develop. Symptoms include weight gain (including fat between the shoulders or above the clavicles), a blushed and puffy face, increased hair growth, muscle weakness, high blood pressure and unexplained mood swings.
- If it is a thyroid stimulating tumour (TSH) that causes the thyroid to be overactive (hyperthyroidism) it causes anxiety, tremors and sleep disorders, increased appetite but a loss of weight, a feeling of warmth with fast or irregular heartbeat and frequent bowel movements.
Treatments for Pituitary Adenoma
If you experience any of the symptoms listed above, you should consult a health professional. The examinations and tests to diagnose a pituitary adenoma are various. First, the doctor will perform a hormonal assays of the blood, to determine if the tumour is cerebral; following that, it will then be necessary to perform an MRI to discover the characteristics of the tumour.
Medication
Pituitary adenoma cannot be eliminated by taking medication. However, some drugs can lead to a decrease in the size of the adenoma, or even to the blockage of the excessive secretion of hormones.
Medications can also be prescribed before an operation, to improve its chances of success.
Surgery
Most pituitary adenomas, whether micro or macro, secreting or not, are removed surgically, and then radiotherapy is done to "clean" the area. After treatment, the patient should be checked regularly to ensure that the functionality of the pituitary gland and hormonal secretion are normal.
The operation takes place under general anaesthetic and lasts between 45 minutes and one hour. The neurosurgeon can choose two techniques for the operation:
- The "sublabial" way: an incision is made under the upper lip and above the gum so that the neurosurgeon can reach the sella turcica (a deep depression in the floor of the skull where the pituitary rests) while passing under the nose.
- The "endonasal" route: the surgeon passes through a nostril to reach the bottom of the nasal cavity and the sella turcica.
The difficulty of the surgery lies in the removal of the adenoma whilst not damaging the pituitary gland. In about 95% of the cases damaging the pituitary gland is avoided by observing the difference in appearance, colour and consistency between the pituitary gland and the adenoma. If the adenoma is not very visible, there is a risk that the healthy gland is damaged or that the adenoma is not completely removed.
At the end of the procedure, a plug is usually placed in each nostril for two to three days in order to avoid an epistaxis (nasal bleeding) and to promote faster healing.
The operation is painless. However, patients may experience headaches above the eyes and mild nasal dryness. It is not recommended to blow your nose for a few days.
Sources: Endoscoop; French Society of Neurosurgery
Published 6 Jun 2018
