Pituitary cancer is a cancerous tumor that begins in the pituitary gland. Doctors may find pituitary cancer if it spreads to other areas of the body.

Most pituitary tumors are benign. Cancerous pituitary tumors, or pituitary carcinomas, are rare.

Treatment may include surgery to remove the tumor, radiation therapy, and drug therapies such as chemotherapy.

This article looks at symptoms, causes, diagnosis, and treatment options for pituitary cancer.

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In the United States, more than 10,000 diagnoses of pituitary tumors occur every year. Only a few are cancerous.

The pituitary gland is a small organ at the base of the brain. It creates hormones and controls how other glands produce hormones.

Pituitary carcinomas may be functioning or nonfunctioning.

Functioning tumors produce excess hormones, which can affect various systems in the body and cause symptoms. Nonfunctioning tumors do not cause excess hormones.

Pituitary carcinomas are usually functioning tumors and produce hormones. Most pituitary carcinomas occur in older adults.

Symptoms of pituitary carcinoma may depend on whether it is functioning or nonfunctioning.

General symptoms of a pituitary tumor may include:

Symptoms of a nonfunctioning pituitary tumor may occur due to the tumor pressing on parts of the pituitary gland and causing a change in hormones. People may experience:

Symptoms of a functioning pituitary tumor depend on which hormone is in excess but may include:

According to the American Cancer Society, the exact cause of pituitary tumors is unknown, but research suggests that certain changes to the DNA of pituitary cells may lead to tumors forming.

Mutations in certain genes can lead to certain cells growing out of control and may turn off tumor suppressor genes, which help to control normal cell division and growth.

People may inherit genetic mutations from their family, or they can acquire the mutations at some point in their life.

There are no known environmental or lifestyle factors that cause pituitary tumors, so there is currently no known way to prevent them.

Risk factors for pituitary tumors include a family history of pituitary tumors and certain genetic conditions, including:

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

Pituitary carcinomas can be difficult to diagnose because, under a microscope, they appear the same as pituitary adenomas. Pituitary adenomas are a type of benign tumor of the pituitary gland.

Doctors, therefore, usually diagnose pituitary carcinomas once they have spread to distant areas of the body. This is the only way doctors know a pituitary tumor is cancerous.

Pituitary carcinomas may spread into other parts of the brain or to the spinal cord. In rare cases, pituitary carcinomas spread to organs such as the lungs, liver, or heart.

Doctors can take a medical history and carry out a physical examination to check for any lumps or other unusual signs.

To diagnose pituitary carcinoma, a doctor may use tests such as:

  • eye exam, including a field of vision test
  • neurological exam to check central nervous system function and mental status
  • MRI scan with an injection of gadolinium, which collects around any cancer cells present
  • blood tests to check for disease markers and hormone levels
  • urine test to check for substances that may indicate disease
  • dexamethasone suppression tests, in which people take high or low doses of dexamethasone to check how much cortisol the adrenal gland is producing, which may indicate a pituitary tumor
  • venous sampling, which takes a blood sample from veins supplying the pituitary gland to check adrenocorticotropic hormone (ACTH) levels
  • biopsy, which examines a tissue or cell sample under a microscope for cancer cells

If surgery is a suitable option, it is usually the first treatment people will receive for pituitary carcinomas.

Surgery aims to remove the tumor and may also remove any areas of cancer that have spread to different parts of the body.

People may also have radiation therapy to shrink the tumor before having surgery. If surgery is not a suitable option for some people, they may have radiation therapy to remove or shrink the tumor.

If people have a functional pituitary carcinoma, doctors can try using the same medications they use to treat pituitary adenomas.

People may require higher doses of these medications or combinations of medications to treat pituitary carcinomas.

In some cases, people may have drug therapies that include chemotherapy and targeted therapy drugs.

Doctors may use temozolomide, a chemotherapy drug, as the first medication option for pituitary carcinomas, potentially alongside radiation therapy.

Pituitary carcinomas are very rare, so currently, it is not clear which treatment approach is the most effective.

A person may want to discuss taking part in a clinical trial with healthcare professionals. Clinical trials may be looking into new treatment options for pituitary carcinomas.

Pituitary carcinomas are very rare. Most pituitary tumors are benign. The majority of pituitary carcinomas produce excess hormones, so people may experience symptoms.

Treatment for pituitary carcinomas includes surgery to remove the cancer, radiation therapy, chemotherapy, and targeted therapy.