Pituitary Adenoma – Causes, Symptoms, Diagnosis, And Treatment
What is pituitary adenoma?
A pituitary adenoma is a noncancerous tumor that grows in the pituitary gland. The pituitary gland is located below the brain and above the nasal passages.
About 20% people have pituitary adenomas. Most of these tumors don’t cause symptoms and are never diagnosed during the person’s lifetime.
What are the functions of the pituitary gland?
The pituitary gland is part of the endocrine system. It helps control the release of hormones from other endocrine glands, such as the thyroid, sex glands (testes or ovaries), and adrenal glands. The pituitary gland also releases hormones that directly affect body tissues, such as bones and the breast milk glands. The following are the hormones released by pituitary gland:
- Adrenocorticotropic hormone (ACTH)
- Growth hormone (GH)
- Thyroid-stimulating hormone (TSH)
- Luteinizing hormone (LH) and follicle-stimulating hormone (FSH)
Hormone-releasing cells of the pituitary gland can be damaged as a pituitary adenoma grows. This results in the pituitary gland not producing enough of its hormones. This condition is called hypopituitarism.
What causes pituitary adenoma?
What causes pituitary adenomas is not known to scientists and doctors. Some pituitary adenomas are part of a hereditary disorder called multiple endocrine neoplasia I (MEN I). The pituitary gland can be affected by brain tumors that develop in the same part of the brain, resulting in similar symptoms.
Pituitary adenomas don’t spread to other parts of the body.
What are the symptoms of pituitary adenoma?
Not all pituitary adenomas cause symptoms. Some pituitary adenomas produce an excessive amount of one or more hormones.
As a result, symptoms of one or more of the following conditions can develop:
- Hyperthyroidism (excessive amount of hormones by the thyroid gland)
- Cushing syndrome (due to a high level of cortisol)
- Gigantism (abnormal growth in children) due to a high level of growth hormone
- Acromegaly (due to a high level of growth hormone in adults)
- Nipple discharge
- Irregular or absent menstrual periods in women
- Decreased sexual function in men
The following symptoms may occur due to pressure from a large pituitary adenoma:
- Changes in vision such as double vision, visual field loss, drooping eyelids, or changes in color vision
- Problems with the sense of smell
- Lack of energy
- Nasal drainage of clear fluid
- Nausea and vomiting
How is a pituitary adenoma diagnosed?
Your doctor will perform a physical examination and review the symptoms. During the exam, the doctor will check for signs of an excessive amount of cortisol (Cushing syndrome) or too much growth hormone (acromegaly). The doctor will note any problems with double vision and visual field, such as a loss of side vision, or the ability to see in certain areas.
The doctor may order the following tests to check endocrine functions:
- Cortisol levels (dexamethasone suppression test, urine cortisol test)
- FSH level
- Insulin growth factor-1 (IGF-1) level
- LH level
- Prolactin level
- Testosterone/estradiol levels
- Thyroid hormone levels: free T4 test, TSH test
The doctor may order the following tests to help confirm the diagnosis:
- MRI of head
- Visual fields
How is pituitary adenoma treated?
Treatment of pituitary adenoma includes surgery and medicines to shrink the tumor or to stop excessive hormone production. Sometimes, radiation therapy is also used.
The doctor may prescribe medicines to shrink certain types of tumors.
Surgical removal is recommended if the tumor is large and pressing on the optic nerves (they control vision). Most of the pituitary adenomas can be surgically removed through the nose and sinuses. When it is not possible to remove the tumor this way, it can be removed through the skull.
The doctor may prescribe radiation therapy to shrink the tumor for people who cannot have surgery. Radiation may also be used if the tumor returns after surgery.
This feature is for informational purposes only and is not intended to substitute the expert guidance of a doctor. We advise seeing a doctor if you have any health concerns.