What Are Pituitary Tumors?

Pituitary tumors are abnormal growths that develop in or near the pituitary gland, a small hormone-producing gland at the base of the brain. Many pituitary tumors are benign pituitary adenomas, and some may also be called pituitary neuroendocrine tumors or PitNETs in newer medical terminology.

Pituitary tumors may be functioning, meaning they make excess hormones, or nonfunctioning, meaning they do not produce extra hormones but may still cause symptoms by pressing on nearby structures. Larger pituitary tumors, called macroadenomas, can press on the optic nerves or optic chiasm and cause vision changes.

De Novo Brain & Spine evaluates adult patients with suspected or confirmed pituitary tumors to help determine the appropriate next step. Evaluation may include neurological examination, pituitary MRI, CT imaging, hormone testing, visual field testing, observation, surgical consultation, or coordination with endocrinology, ophthalmology, radiation oncology, or other specialists when needed.

Common Signs and Symptoms

Pituitary tumor symptoms depend on the tumor’s size, hormone activity, growth pattern, and pressure on the optic nerves, optic chiasm, pituitary gland, or nearby skull base structures. Some pituitary tumors are found incidentally on imaging and may not cause symptoms.

Common signs and symptoms may include:

• Headaches
• Blurred vision, double vision, or loss of peripheral vision
• Fatigue or low energy
• Unexplained weight gain or weight loss
• Menstrual changes or infertility
• Sexual dysfunction or low libido
• Breast milk production not related to pregnancy or breastfeeding, called galactorrhea
• Symptoms of excess prolactin, called hyperprolactinemia
• Enlarged hands, feet, jaw, or facial features from excess growth hormone, called acromegaly
• Easy bruising, muscle weakness, weight gain, high blood pressure, or blood sugar changes from excess cortisol, called Cushing disease
• Symptoms of thyroid hormone imbalance when thyroid-stimulating hormone is affected
• Increased thirst or urination in selected cases
• Nausea, dizziness, or low blood pressure when pituitary hormone deficiency affects adrenal function

Seek emergency medical care or call 911 for sudden severe headache, sudden vision loss, double vision with eye movement problems, confusion, fainting, loss of consciousness, or rapid neurological decline. These symptoms may occur with pituitary apoplexy, which is bleeding or sudden swelling within a pituitary tumor.

What Causes This Condition?

Most pituitary tumors develop without a clearly known cause. A diagnosis of a pituitary tumor does not usually mean that the patient did something to cause it.

Possible risk factors and related medical factors may include:

• Rare inherited endocrine tumor syndromes, such as multiple endocrine neoplasia type 1, also called MEN1
• Familial pituitary tumor conditions, such as familial isolated pituitary adenoma
• Rare genetic conditions that may be associated with endocrine tumors
• Tumor-specific hormone activity, such as prolactin, growth hormone, ACTH, or thyroid-stimulating hormone production

Doctors may also classify pituitary tumors by size and function. A pituitary microadenoma is smaller than 10 millimeters, while a pituitary macroadenoma is 10 millimeters or larger. A functioning pituitary tumor produces excess hormone, while a nonfunctioning pituitary tumor does not produce excess hormone but may still cause pressure-related symptoms.

These classifications are not lifestyle causes. They help doctors understand the tumor’s behavior and guide treatment planning.

How It Is Diagnosed?

Pituitary tumors cannot be diagnosed by symptoms alone. Diagnosis usually requires medical history, neurological examination, pituitary imaging, hormone testing, and sometimes visual testing.

Common diagnostic steps may include:

• Medical history and neurological examination to evaluate headaches, vision, eye movements, strength, sensation, balance, memory, and symptoms of hormone imbalance
• MRI of the brain and pituitary gland with and without contrast, often the main imaging study used to evaluate a pituitary tumor
• Pituitary-protocol MRI to provide detailed images of the sellar and parasellar region
• CT scan of the head or skull base in selected cases, especially when bone anatomy, calcification, or urgent symptoms need evaluation
• Blood, urine, or saliva hormone testing to evaluate pituitary and endocrine function
• Prolactin testing when a prolactinoma is suspected
• IGF-1 and growth hormone evaluation when acromegaly is suspected
• ACTH and cortisol testing when Cushing disease is suspected
• Thyroid, adrenal, reproductive, and other pituitary hormone testing when hormone deficiency or hormone excess is possible
• Visual field testing and ophthalmologic examination when the tumor is near the optic nerves or optic chiasm
• Inferior petrosal sinus sampling in selected cases of suspected Cushing disease when the source of ACTH production is unclear
• Pathology review when tissue is removed during surgery to confirm tumor type

The goal of diagnosis is to determine the tumor’s size, location, hormone activity, effect on vision, and relationship to nearby brain and skull base structures.

Treatment Options

Pituitary tumor treatment depends on the tumor’s size, hormone activity, symptoms, vision findings, imaging results, growth over time, surgical risk, and the patient’s overall health. Not every pituitary tumor requires surgery.

Treatment options may include:

• Observation with repeat MRI scans for selected small, stable, nonfunctioning tumors that are not causing symptoms or vision problems
• Endocrinology management to evaluate and treat hormone excess or hormone deficiency
• Dopamine agonist medication, such as cabergoline or bromocriptine, for many prolactin-secreting tumors, called prolactinomas
• Medical therapy for hormone-producing tumors when appropriate, including selected treatments for acromegaly, Cushing disease, or other endocrine syndromes
• Endoscopic endonasal transsphenoidal surgery, a surgical approach through the nasal corridor and sphenoid sinus, when tumor removal is appropriate
• Craniotomy in selected cases when tumor anatomy, extension, or surrounding structures make an open approach more appropriate
• Maximal safe tumor resection, which means removing as much tumor as safely possible while protecting the pituitary gland, optic nerves, optic chiasm, carotid arteries, and nearby brain structures
• Radiation therapy or stereotactic radiosurgery in selected cases involving residual tumor, recurrent tumor, tumor growth, or hormone activity not controlled by other treatments
• Emergency treatment for pituitary apoplexy when sudden bleeding or swelling causes severe headache, vision loss, eye movement problems, or hormone crisis
• Long-term follow-up with MRI, hormone testing, and vision monitoring when appropriate

Surgery may be considered when a pituitary tumor causes vision problems, compresses the optic apparatus, grows over time, causes certain hormone problems, fails appropriate medical therapy, or requires tissue diagnosis. The safest treatment plan depends on the tumor type, anatomy, hormone activity, and the patient’s individual condition.