General Information About Pituitary Tumors
A pituitary tumor is a growth of abnormal cells in the tissues of the pituitary gland.
Pituitary tumors form in the pituitary gland, a pea-sized organ in the center of the brain, just above the back of the nose. The pituitary gland is sometimes called the "master endocrinegland" because it makes hormones that affect the way many parts of the body work. It also controls hormones made by many other glands in the body.
Anatomy of the inside of the brain, showing the pineal and pituitary glands, optic nerve, ventricles (with cerebrospinal fluid shown in blue), and other parts of the brain.
Pituitary tumors are divided into three groups:
- Benign pituitary adenomas: Tumors that are not cancer. These tumors grow very slowly and do not spread from the pituitary gland to other parts of the body.
- Invasive pituitary adenomas: Benign tumors that may spread to bones of the skull or the sinus cavity below the pituitary gland.
- Pituitary carcinomas: Tumors that are malignant (cancer). These pituitary tumors spread into other areas of the central nervous system (brain and spinal cord) or outside of the central nervous system. Very few pituitary tumors are malignant.
Pituitary tumors may be either non-functioning or functioning.
- Non-functioning pituitary tumors do not make hormones.
- Functioning pituitary tumors make more than the normal amount of one or more hormones. Most pituitary tumors are functioning tumors. The extra hormones made by pituitary tumors may cause certain signs or symptoms of disease.
The pituitary gland hormones control many other glands in the body.
Hormones made by the pituitary gland include:
- Prolactin: A hormone that causes a woman's breasts to make milk during and after pregnancy.
- Adrenocorticotropic hormone (ACTH): A hormone that causes the adrenal glands to make a hormone called cortisol. Cortisol helps control the use of sugar, protein, and fats in the body and helps the body deal with stress.
- Growth hormone: A hormone that helps control body growth and the use of sugar and fat in the body. Growth hormone is also called somatotropin.
- Thyroid-stimulating hormone: A hormone that causes the thyroid gland to make other hormones that control growth, body temperature, and heart rate. Thyroid-stimulating hormone is also called thyrotropin.
- Luteinizing hormone (LH) and follicle-stimulating hormone (FSH): Hormones that control the menstrual cycle in women and the making of sperm in men.
Having certain genetic conditions increases the risk of developing a pituitary tumor.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Risk factors for pituitary tumors include having the following hereditary diseases:
- Multiple endocrine neoplasia type 1 (MEN1) syndrome.
- Carney complex.
- Isolated familial acromegaly.