Pituitary Tumor
A usually benign growth in the body's master hormone gland
Quick Facts
- Type: Endocrine and brain-region tumor
- Nature: Most are benign (non-cancerous)
- Main effects: Hormone changes, vision problems, headache
- Specialist: Endocrinology and neurosurgery
Overview
A pituitary tumor is an abnormal growth in the pituitary gland, a small, pea-sized gland at the base of the brain often called the body's master gland because it controls many other hormone-producing glands. Most pituitary tumors are benign (non-cancerous) growths called adenomas, and many grow slowly. Cancerous pituitary tumors are very rare.
Even though they are usually benign, pituitary tumors can cause significant problems in two main ways: some produce excess hormones that disturb the body's balance, and larger tumors can press on nearby structures, including the nerves that carry vision. Some pituitary tumors cause no symptoms and are found by chance. With appropriate treatment, including medication, surgery, or radiation, most pituitary tumors can be managed effectively.
Symptoms
Symptoms depend on whether the tumor produces hormones and on its size:
- From excess hormones: Unexpected milk production, missed periods, low sex drive, infertility, growth of hands and feet (acromegaly), weight gain and other features of high cortisol, or symptoms of an overactive thyroid.
- From pressure of a larger tumor: Headaches and vision problems, especially loss of side (peripheral) vision.
- From reduced hormones: Fatigue, weakness, weight changes, and feeling cold, if the tumor impairs normal pituitary function.
Sudden, severe headache with vision changes can rarely signal bleeding into a tumor, which is an emergency.
Causes
In most cases, the exact cause of a pituitary tumor is not known. They develop from changes in the cells of the pituitary gland that cause them to grow abnormally. Important points include:
- Usually sporadic: Most occur without a clear inherited cause.
- Genetic syndromes: A small number are linked to inherited conditions, such as multiple endocrine neoplasia, that increase the risk of pituitary and other gland tumors.
Unlike many cancers, pituitary tumors are not clearly linked to lifestyle factors, and most cannot be prevented.
Risk Factors
- A family history of pituitary tumors
- Inherited endocrine syndromes such as multiple endocrine neoplasia type 1
Most people who develop a pituitary tumor have no identifiable risk factors, and the tumors occur across a wide range of ages.
Diagnosis
Diagnosis combines hormone testing, imaging, and vision assessment:
- Blood and urine tests: To measure pituitary and related hormones and detect overproduction or underproduction.
- MRI of the brain: The best imaging test to see the size and location of the tumor.
- Vision testing: To check for loss of side vision when a larger tumor is present.
Sometimes a pituitary tumor is discovered incidentally on a scan done for another reason, prompting further hormone and vision evaluation.
Treatment
Treatment depends on the type and size of the tumor and the hormones involved:
- Observation: Small tumors that cause no symptoms may simply be monitored with periodic scans.
- Medication: Certain hormone-producing tumors, such as prolactinomas, can often be controlled with medicine that shrinks them and normalizes hormones.
- Surgery: Removal of the tumor, frequently through the nose and sinuses, for tumors causing pressure or excess hormones not controlled by medicine.
- Radiation therapy: Used when surgery is incomplete or not possible.
- Hormone replacement: If the pituitary cannot make enough hormones after the tumor or its treatment.
Prevention
- Most pituitary tumors cannot be prevented, since their cause is usually unknown
- People with inherited endocrine syndromes may be monitored for early detection
- Reporting symptoms such as vision changes, persistent headaches, or hormone-related changes allows earlier diagnosis
When to See a Doctor
See a doctor if you have unexplained hormone-related changes, such as missed periods, unexpected milk production, low sex drive, or changes in the size of your hands and feet, or persistent headaches and vision problems, especially loss of side vision. Seek emergency care for a sudden, severe headache with vision loss, double vision, or confusion, which can rarely signal bleeding into a pituitary tumor and needs urgent treatment.
Frequently Asked Questions
Are pituitary tumors cancerous?
Most pituitary tumors are benign, non-cancerous growths called adenomas, and cancerous pituitary tumors are very rare. Even benign tumors can cause problems by producing excess hormones or pressing on nearby structures, so they often still need treatment.
How does a pituitary tumor affect vision?
A larger pituitary tumor can press on the nerves that carry vision, which sit just above the gland. This typically causes loss of side (peripheral) vision and should be evaluated promptly, as treating the tumor can often protect or restore sight.
What are the symptoms of a pituitary tumor?
Symptoms vary. Hormone-producing tumors can cause missed periods, unexpected milk production, low sex drive, or growth of the hands and feet, while larger tumors may cause headaches and vision loss. Some tumors cause no symptoms and are found by chance.
How is a pituitary tumor treated?
Treatment depends on the tumor type and size and may include observation, medication that can shrink certain tumors, surgery often performed through the nose, and radiation therapy. Hormone replacement may be needed if the pituitary cannot make enough hormones.
Can a pituitary tumor be cured?
Many pituitary tumors can be effectively controlled or removed with medication, surgery, or radiation. Some hormone-producing tumors respond very well to medicine, and the great majority of people are managed successfully with appropriate care.
References
- National Cancer Institute (NCI). Pituitary tumors treatment.
- Mayo Clinic. Pituitary tumors — Symptoms and causes.
- MedlinePlus, U.S. National Library of Medicine. Pituitary tumors.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Pituitary disorders.