Although small, the pituitary gland located at the base of the brain is the command center for the body’s endocrine system, secreting prolactin, ACTH, thyroid, growth hormone and sex hormones. Pituitary tumors make up about 12 percent of all primary brain tumors. The vast majority of pituitary tumors are slow-growing non-cancerous adenomas. Some pituitary tumors cause excessive production of hormones that regulate important functions of your body. Other pituitary tumors can restrict normal functions of your pituitary gland, causing it to produce lower levels of hormones. Many tumors are asymptomatic and discovered incidentally through imaging for another condition. They may not need treatment.
Founded in March 2010, the Comprehensive Pituitary Center at Washington University School of Medicine and Barnes-Jewish Hospital is the first multidisciplinary center in the region dedicated to diagnosing and treating patients with pituitary tumors. When symptoms do arise, the Center draws on the combined expertise of a variety of specialties: endocrinology, neuro-ophthalmology, radiation oncology, otolaryngology, neuroradiology, neuropathology and neurosurgery.
Typically, patients are seen by the endocrinologist and a neurosurgeon the same day and have expedited referrals to other pertinent specialties, such as otolaryngology and radiology. Every patient with a pituitary tumor should have an endocrine work-up to see if the tumor is creating hormone issues. Specialty testing for an accurate diagnosis is not available at some community hospitals, so the center works with referring physicians in partnership. When needed, treatment may be aimed at removing the tumor, controlling its growth with radiotherapy, or managing hormone levels with medications.
Types of Pituitary Lesions
- Functioning pituitary adenomas: These benign pituitary adenomas (tumors) cause the body to make too much of certain hormones:
Prolactin stimulates breast growth and milk production in women. Prolactin secreting tumor, a prolactinoma, is the most frequent type of functioning pituitary adenoma.
Growth hormone plays a part in height in children and the body’s metabolism. Tumors that make too much cause acromegaly or gigantism (gradual enlargement of body parts), and are called somatotroph adenomas.
Adrenocorticotropic hormone (ACTH) tells the adrenal glands to make cortisol, and helps regulate blood pressure and heart function. Too much ACTH leads to Cushing’s disease (excess weight gain, thin skin and easy bruising), and these functioning adenomas are called corticotroph adenomas.
Thyroid-stimulating hormone (TSH) regulates our thyroid. Pituitary tumors that make too much of this hormone cause hyperthyroidism. This type is rare.
Although Cushing’s disease and acromegaly are rare, the Pituitary Center treats a large number of patients with these conditions.
- Non-functioning pituitary adenomas: This type of pituitary adenoma does not make hormones and is the second most frequent type of pituitary adenoma. They cause problems by growing large and pressing against structures like the optic or other nerves, or reducing normal hormone production. Large tumors can produce symptoms such as headaches or loss of vision, especially peripheral vision.
- Craniopharyngioma: This benign tumor begins near the pituitary gland located near the base of the brain and is very slow-growing. These tumors are rare, making up less than 1 percent of all brain tumors.
- Rathke’s cleft cyst: These are benign fluid-filled cysts in the sellar region.
- Pituitary cancer: In rare cases, the cells in a pituitary adenoma tumor can become cancerous and spread to other areas of the body.
Medical Options for Pituitary Tumors
The Center has long experience with specialty medications for functional tumors, as well as new approved drugs for treating acromegaly and Cushing’s disease. They can also replace hormones for nonfunctional tumors.
An Innovative Surgical Option for Removal of Pituitary Tumors
Gamma Knife radiotherapy: Using specialized equipment, close to 200 tiny beams of radiation are focused on a tumor or other target. Although each beam has very little effect on the brain tissue it passes through, a strong dose of radiation is delivered to the site where all the beams meet. Its precision results in minimal damage to healthy tissues around the tumor. Gamma Knife is also effective for tumors around the pituitary gland, such as cavernous sinus meningiomas, which may have a high surgical morbidity due to proximity of important cranial nerves to the tumor.
The Comprehensive Pituitary Center allows specialists the opportunity to deliver state-of-the-art patient care and novel treatment. They use a customized approach for each individual by selecting treatments from an array of innovative options, including the surgical options above, medications, and other radiation therapy approaches such as Proton Beam, and Fractionated Radiotherapy. Because the physicians on the team have long-standing experience and specialized training regarding pituitary pathologies, they are able to treat even the most challenging cases.