Pituitary adenomas are mostly benign tumors arising from the pituitary gland, which regulates the body's hormones. They can cause symptoms through hormone excess or by pressing on the optic nerves.
What is a pituitary adenoma?
The pituitary gland is a small gland at the base of the brain, sitting in a bony hollow of the skull base called the sella turcica, and it regulates many of the body's hormones. Pituitary adenomas are tumors arising from this gland; the great majority are benign.
Adenomas are divided into two groups depending on whether they produce hormones:
- Functioning (hormone-secreting) adenomas: May cause excess prolactin, growth hormone (acromegaly), ACTH (Cushing's disease) or, rarely, TSH.
- Non-functioning adenomas: Usually cause symptoms when they grow and press on the optic nerves and the normal pituitary tissue.
Adenomas smaller than 1 cm are called microadenomas; larger ones are called macroadenomas.
Symptoms
- Visual disturbance, particularly loss of the outer parts of the visual field
- Headache
- Menstrual irregularity, milky breast discharge, reduced libido and infertility (prolactinoma)
- Enlargement of the hands and feet, coarsening of facial features and excessive sweating (acromegaly)
- Weight gain, rounding of the face, high blood pressure and high blood sugar (Cushing's disease)
- Weakness and fatigue (pituitary insufficiency)
Diagnosis
Diagnosis combines thin-section contrast-enhanced MRI of the pituitary region, detailed blood and urine hormone tests, and eye examination with visual field testing. Evaluation is carried out jointly with endocrinology.
Treatment Approach
- Medication: Medication is usually the first treatment for prolactin-secreting adenomas (prolactinomas); in most patients the tumor shrinks and hormone levels return to normal.
- Endoscopic transsphenoidal surgery: Most pituitary adenomas can be removed through the nose using an endoscope, without opening the skull. It is the main treatment for adenomas that press on the optic nerves or cause hormone excess.
- Radiosurgery: Gamma Knife radiosurgery may be used for residual or recurrent tumor after surgery and for parts extending into the cavernous sinus, aiming both to control the tumor and to reduce hormone excess.
- Observation: Small, non-functioning adenomas that cause no symptoms can be monitored with MRI.