Facts About Pituitary Tumors and Disorders

January 8, 2026

This page was reviewed under our medical and editorial policy by Behrouz Salehian M.D., clinical professor, Department of Diabetes, Endocrinology & Metabolism, City of Hope^® Cancer Center Duarte.

The pituitary gland is a small organ at the base of the brain, but it plays a big role in keeping the body healthy. Labeled the “master gland,” due to its secretion of nine major hormones, it helps control important functions like growth, blood pressure, milk production, urine concentration ability, energy balance and reproduction. Because it has such an important job, any problem or tumor in the pituitary gland needs careful attention and possibly treatment.

What Is the Pituitary Gland?

The pituitary gland is a pea-sized organ located at the base of the brain, just behind the nose. Like a thermostat, it constantly monitors body functions and makes hormones that control them — like growth, metabolism, stress response and reproduction. It also helps other glands in the body, like the thyroid and adrenal glands, work properly.

How Common Are Pituitary Disorders?

Each year, more than 10,000 pituitary tumors are diagnosed in the U.S., and most are benign. They’re considered rare, but the actual number may be much higher. In fact, up to 1 in 4 people may have one without ever knowing, since many are small and cause no symptoms.

Though pituitary tumors can happen at any age, they are most often found in older adults.

Types of Pituitary Disorders

A variety of issues may affect the pituitary gland, including disorders like inflammation affecting its function and tumors. The majority of tumors are benign, but very rarely may be cancerous.

Pituitary Tumor

The pituitary gland may be affected by many different conditions, most often by growths called tumors. The majority of these tumors are not cancerous and may never cause serious problems. In rare cases, however, they may be malignant (cancerous).

Pituitary Adenoma

A pituitary adenoma is a non-cancerous tumor of the pituitary gland. Most are small and grow slowly, sometimes causing symptoms if they press on nearby structures or make too much of certain hormones. The exact cause isn’t clear, but changes in the DNA of pituitary cells may trigger abnormal growth.

Pituitary Carcinoma and Pituitary metastasis.

A pituitary carcinoma is a very rare cancerous tumor of the pituitary gland. Unlike adenomas, these tumors may grow more quickly and spread to other parts of the body. The causes are not well understood, but researchers suggest that changes in the DNA of pituitary cells play a role. Rarely, malignant tumors from the breasts or kidneys may metastasize to the pituitary gland, causing symptoms such as pituitary dysfunction.

Pituitary Cyst

A pituitary cyst is a fluid-filled sac on or in the pituitary gland. Most are harmless and don’t cause symptoms, but some can grow large enough to affect hormone levels or press on nearby structures. They usually form during development, but the exact reason they appear isn’t fully known.

Are Pituitary Tumors Cancerous?

A very small number of pituitary tumors are cancerous. These cancerous tumors grow more quickly than benign tumors, and require more intensive treatment to manage. The vast majority of pituitary tumors are benign, meaning they’re not cancerous and don’t spread to other parts of the body.

Are Pituitary Tumors Hereditary?

Most pituitary tumors are not inherited and usually happen by chance. In other words, they don’t typically run in families.

However, in some cases, pituitary tumors may be linked to certain inherited conditions that are caused by changes (mutations) in a person’s genes, including:

• Multiple endocrine neoplasia, type 1 (MEN1)
• Multiple endocrine neoplasia, type 4 (MEN4)
• McCune-Albright syndrome
• Carney complex
• Familial isolated pituitary adenoma (FIPA)

These conditions may increase the risk of pituitary tumors, and if several family members have pituitary or other endocrine tumors, the patient’s doctor may recommend genetic testing.

Acromegaly

Acromegaly happens when the pituitary gland makes too much growth hormone (GH), usually because of a benign tumor. This causes body parts like the hands, feet and face to grow larger over time.

Cushing Syndrome

This condition occurs when the body has too much cortisol, a stress hormone. It’s often caused by a pituitary tumor that makes extra ACTH (adrenocorticotropin hormone), which signals the adrenal glands to overproduce cortisol.

Diabetes Insipidus

Diabetes insipidus may happen when the pituitary gland is not able to secrete anti-diuretic hormone (arginine-vasopressin) and concentrate the urine. Consequently, the body can’t balance fluids properly. Another cause of diabetes insipidus is the inability of the kidneys to concentrate the urine (nephrogenous diabetes insipidus).

Empty Sella Syndrome

When the area in the skull where the pituitary gland sits (the sella) looks “empty” on scans, it’s called empty sella syndrome. It can happen if the pituitary shrinks or flattens, sometimes causing hormone problems, but often causing no symptoms.

Hypopituitarism

Hypopituitarism develops when the pituitary gland doesn’t make enough of one or more of its hormones. Among the causes are tumors, surgery, radiation therapy or other damage to the gland due to chronic or acute inflammation. With new immunotherapy for cancers, inflammation of the pituitary gland may happen and lead to hypopituitarism.

Lymphocytic Hypophysitis

This rare condition — more common in women, especially during or after pregnancy — happens when the body’s immune system mistakenly attacks the pituitary gland, causing swelling and low hormone levels.

Prolactinoma

A prolactinoma is a benign pituitary tumor that makes too much prolactin, a hormone linked to breast milk production, often causing symptoms like irregular periods, infertility or breast milk leakage.

Sheehan Syndrome

Sheehan syndrome arises when severe blood loss during childbirth damages the pituitary gland. The gland can’t make enough hormones, leading to an inability to breastfeed, loss of the menstrual period, chronic fatigue, low blood pressure and other health problems. Usually the diagnosis is made several years, if not decades, after the hemorrhagic event.