Some doctors may classify pituitary tumors as brain tumors, although others may not. Brain tumors occur in brain tissue, whereas pituitary tumors originate in the pituitary gland, which is inside the skull but not part of the brain.

According to the American Cancer Society (ACS), around 10,000 pituitary tumors are diagnosed each year. Symptoms include vision problems and changes in hormone levels.

This article will explain the difference between a brain tumor and a pituitary tumor. It will also outline the symptoms and treatment of a pituitary tumor, as well as the causes, risk factors, and outlook.

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Technically, a pituitary tumor is not a brain tumor because the pituitary gland is not located in the brain. It is found at the base of the skull, below the brain and above the nasal passages. The Pituitary Foundation states that pituitary tumors are not brain tumors, as the pituitary gland is close to the brain but not part of it.

However, there is debate on the subject, as some doctors and healthcare professionals do define them as brain tumors. A 2021 article in Frontiers in Endocrinology calls pituitary tumors the second most common primary brain tumor arising in humans.

Doctors may sometimes refer to pituitary tumors as brain tumors to simplify the conversation.

The National Cancer Institute defines a tumor as an abnormal mass of tissue.

Usually, the body makes enough new cells to replace those that die. Sometimes, cells can start to grow uncontrollably or fail to die when they should. This can lead to a buildup of cells and create tumors.

There are two general types of tumors:

  • Benign tumors: Benign tumors are not cancerous. They can grow into large masses, but they do not spread into other parts of the body.
  • Malignant tumors: Malignant tumors are cancerous and can spread into other parts of the body.
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Tumors can develop in any part of the body.

When tumors start in the pituitary gland, doctors tend to call them pituitary tumors. Brain tumors are ones that begin in the brain.

Doctors may refer to pituitary gland tumors as brain tumors for simplicity.

Learn more about tumors.

The pituitary gland is a small gland at the base of the skull, located below the brain and above the nasal passages. It connects to a part of the brain known as the hypothalamus. An abnormal growth in the pituitary gland is a pituitary tumor.

Glands are organs that produce and release substances or hormones in the body that have specific functions. The ACS says most pituitary tumors are benign and do not spread to other parts of the body.

Doctors may call these tumors “pituitary adenomas.” While they are not cancerous, they can:

  • press on nerves or nearby parts of the brain
  • grow into nearby structures, such as the sinuses or the skull
  • cause the gland to make excess hormones or affect their ability to make hormones properly

Pituitary cancers are rare. Doctors may also call them pituitary carcinomas or metastatic PitNETs.

Not all pituitary tumors will cause symptoms.

If the tumor is pressing on or has grown into nearby structures, symptoms may include:

  • eye problems, such as blurred vision, double vision, loss of peripheral vision, or gradual blindness
  • headaches
  • numbness or pain in the face
  • dizziness
  • loss of consciousness

If the tumor has changed the way the gland makes hormones, symptoms may include:

  • feeling tired or weak
  • feeling cold
  • unexpectedly losing or gaining weight
  • losing body hair
  • low blood pressure
  • having less interest in sex
  • for males, trouble getting or maintaining an erection, or the growth of breast tissue
  • for females, changes in menstrual cycles or periods stopping

Sometimes, large tumors can lead to a condition doctors call diabetes insipidus. This condition makes the body produce too much urine. Symptoms include:

  • needing to urinate more often during the day and the night
  • passing large volumes of light-colored urine every time
  • feeling very thirsty

Learn more about the symptoms of a pituitary tumor.

A person who experiences the symptoms of a pituitary tumor, such as eye problems or headaches, should speak with a doctor as soon as possible.

However, many pituitary tumors do not cause symptoms. When this is the case, doctors tend to find them when investigating another issue.

Doctors do not know what causes pituitary gland tumors. However, there are some things that make developing one more likely.

The risk factors for pituitary tumors include:

  • having a genetic syndrome such as:
    • multiple endocrine neoplasia, either type 1 (MEN1) or type 4 (MEN4)
    • McCune-Albright syndrome, which can cause bone issues
    • Carney complex, which can cause changes in skin tone
  • in rare cases, having a family member with a pituitary tumor

Doctors will usually recommend one or a combination of the following treatments:

  • surgery to remove the tumor through the nasal cavity
  • radiation to kill the abnormal cells
  • medication to help restore hormone levels

Learn more about medications for pituitary tumors.

Doctors tend to measure outlook according to 5-year survival rates. This refers to the percentage of people who they would expect to be alive 5 years after the diagnosis.

The 5-year survival rate for people with a pituitary tumor is 97%.

A pituitary tumor develops in the pituitary gland, which sits at the base of the skull, above the nasal passages. Sometimes, healthcare professionals will call a pituitary tumor a brain tumor for simplicity. However, it is worth remembering that the pituitary gland is not technically part of the brain and is not made from brain tissue.

Pituitary tumors are rarely cancerous. However, they can press on or grow into other nearby nerves and structures, causing symptoms. They can also interfere with how the pituitary gland works, thereby affecting all the body’s other glands as well.

Doctors will usually carry out blood, urine, physical, and imaging tests to diagnose a pituitary tumor. Treatment may include surgery, radiation, and medication.