Pituitary Tumors: Patient Guide

This page is for people told they have a pituitary tumor and their families. It covers the tumor types, symptoms, emergencies, tests, and treatment.

The pituitary is a pea-sized gland at the base of the brain. It sits in a bony pocket called the sella turcica and directs much of the body's hormone system.

NCI's PDQ summary reports that pituitary tumors make up 10% to 25% of tumors inside the skull. The overwhelming majority are adenomas, which are benign. Pituitary carcinoma, the malignant form, accounts for only 0.1% to 0.2% of cases.

PDQ also gives an overall estimated prevalence of 17% for adenomas and says few adenomas cause symptoms. So the finding on a scan and the problem in the patient are two separate questions.

Trouble comes from two directions. Either the tumor makes a hormone it should not, or it grows large enough to press on something.

The dividing line is 10 mm across.

• A microadenoma is smaller than 10 mm. Most adenomas fall here.
• A macroadenoma is 10 mm or larger.

PDQ also describes a formal grading system:

• A five-grade scheme runs from 0 through IV. It rates where the tumor sits in the sella and how far it invades.
• A second scale grades how far the tumor grows upward above the sella, from 0 to more than 30 mm, using letters A through D.

PDQ says visual field deficits are one of the most characteristic signs of these tumors.

PDQ gives the share each type holds in surgical specimens.

Prolactin-producing tumors are the most common, at 25% to 41%. Excess prolactin causes missed periods, reduced fertility, and milk production unrelated to nursing. These figures come from the National Cancer Institute’s “Pituitary Tumors Treatment (PDQ).”

Growth hormone-producing tumors account for about 13% in one series. In adults this causes acromegaly. NIDDK describes the changes. The hands and feet become larger and swollen. The lips, nose, and tongue become larger. Skin becomes thick, coarse, and oily. The voice becomes deeper and sweating increases. The brow and lower jaw jut out. PDQ adds carpal tunnel syndrome, snoring and sleep apnea, and osteoarthritis and joint pain.

ACTH-producing tumors account for about 10% in one series. Excess ACTH drives the adrenal glands to overproduce cortisol, which is called Cushing disease. PDQ lists weakness in the muscles closest to the trunk, fat that collects around the middle, stretch marks, easy bruising, thin skin, and thinning bones. NIDDK adds weight gain and a round face. It says wide purple stretch marks show up mainly on the abdomen, breasts, hips, and under the arms.

Thyrotropin-producing tumors are rare, no more than 2% of specimens. They cause an overactive thyroid without the drop in TSH (thyroid-stimulating hormone) you would normally expect. PDQ notes they are often plurihormonal, meaning they make more than one hormone.

Nonfunctioning adenomas make up 30% to 35%. They release no active hormone. Their damage comes from pressing on nearby tissue.

PDQ names two features as the most characteristic signs at diagnosis: the gland releasing hormones it should not, and gaps in the field of vision. Headache is listed among the symptoms of several individual tumor types.

Ask whether formal visual field testing has been done and whether it will be repeated.

PDQ describes apoplexy as an acute hemorrhagic or ischemic infarction of the pituitary. In plain words, it is sudden bleeding into the tumor or loss of its blood supply. PDQ says it often happens in people who did not know they had a tumor. It lists headache, vomiting, and visual field defects among the signs.

• Call 911 or go to the nearest emergency department right away for a sudden severe headache, vomiting, or a sudden loss of vision or change in vision. PDQ does not give an urgency level. The emergency route is the cautious choice.
• Do not wait for a clinic appointment.

Anyone who takes steroid replacement because the gland is underactive has a second emergency to know about. MedlinePlus lists the signs of acute adrenal crisis. They include severe weakness, nausea and vomiting, belly or flank pain, dizziness or lightheadedness, low blood pressure, high fever, and confusion or loss of consciousness.

• Call 911 or go to the nearest emergency department if you have signs of adrenal crisis. MedlinePlus says to go to the emergency room or call the local emergency number.
• Call your team right away, day or night, if illness, vomiting or a missed dose means you cannot take or keep down your steroid tablets. MedlinePlus says to contact your provider if you cannot take your glucocorticoid medicine for any reason.

Imaging and blood work run in parallel.

PDQ says sagittal T1-weighted images and coronal images (views from the side and from the front) are optimal for finding a pituitary adenoma. It says a 3-mm thin slice is typically used.

Hormone testing depends on which syndrome is suspected.

For acromegaly, NIDDK explains why a single growth hormone level is not reliable: GH levels in the blood change throughout the day. A reliable way to track GH is to measure IGF-I in the blood. NIDDK describes an oral glucose tolerance test. You drink a sugary liquid. A health professional then tests your blood every half hour for 2 hours. Sugar normally makes growth hormone levels fall. In acromegaly they stay high.

For Cushing syndrome, NIDDK names three screening tests. One is a 24-hour urinary free cortisol collection. One is a late-night salivary cortisol sample. The third is a low-dose dexamethasone suppression test, in which cortisol should fall after the dose and does not.

NIDDK says the most common cause of Cushing syndrome is the long-term, high-dose use of cortisol-like glucocorticoid medicines. Bring a complete list of your medicines.

NIDDK says pituitary tumors that make too much ACTH cause 8 out of 10 cases of Cushing syndrome not caused by glucocorticoid medicines.

PDQ also links pituitary adenomas to inherited syndromes. Three are named: multiple endocrine neoplasia type 1, Carney complex, and familial acromegaly.

Prolactinomas are usually treated with pills first, not an operation.

PDQ says most prolactinomas respond well to dopamine agonists. The two named are bromocriptine and cabergoline. PDQ puts cabergoline's success rate above 90% in people with newly diagnosed prolactinomas. It also says macroprolactinomas can shrink, sometimes quite dramatically. PDQ says surgery is typically reserved for people who cannot tolerate these drugs, who have apoplexy during treatment, or whose macroprolactinomas do not respond to medicine.

Ask whether prolactin was measured before surgery is planned for a pituitary mass.

PDQ calls the transsphenoidal microsurgical approach the most widely used approach for both hormone-making and nonfunctioning tumors. NCI's patient guide says the surgeon goes in through a cut under the upper lip or at the bottom of the nose. PDQ says remission rates for ACTH-producing tumors are approximately 70% to 90%. NIDDK puts the cure rate for pituitary Cushing disease as high as 90%. That figure assumes a highly experienced surgeon. It is a strong reason to ask how many of these cases your surgeon does.

PDQ says this surgery is contraindicated when the tumor extends well above the sella and has an hourglass-shaped narrowing.

Medical therapy exists for other types too. PDQ calls somatostatin analogues the treatment of choice for TSH-producing tumors. It lists ketoconazole as an option for ACTH-secreting tumors. For growth hormone-producing tumors, PDQ and NIDDK list somatostatin analogs, dopamine agonists, and a growth hormone-receptor antagonist.

PDQ describes radiation as given after surgery when residual or recurrent tumor is shown. Two numbers matter before agreeing to it. PDQ reports about a 30% risk of hypopituitarism at 10 years. That word means the gland becomes underactive. It also says a complete and lasting response may take 2 to 10 years.

MedlinePlus says hypopituitarism usually needs lifelong hormone medicines. Ask who will manage that.

• Was a dedicated pituitary MRI done, or a general brain MRI?
• Which hormones were measured, and were any low as well as high?
• Have I had formal visual field testing, and when is the next one?
• Is this tumor functioning or nonfunctioning, and how was that established?
• If surgery is proposed, how many transsphenoidal cases does this surgeon do per year?
• Will I need hormone replacement afterward, and who will manage it long term?

• https://www.cancer.gov/types/pituitary/hp/pituitary-treatment-pdq
• https://www.niddk.nih.gov/health-information/endocrine-diseases/acromegaly
• https://www.niddk.nih.gov/health-information/endocrine-diseases/cushings-syndrome
• https://medlineplus.gov/ency/article/000357.htm
• https://medlineplus.gov/ency/article/000343.htm
• https://www.cancer.gov/types/pituitary/treatment