Pituitary Adenoma
What is a Pituitary Adenoma?
Overview
A pituitary adenoma (tumor) is a benign (noncancerous) growth on your pituitary gland, a small gland located at the base of the brain.
The pituitary gland is responsible for producing hormones that regulate various bodily functions, including growth, metabolism, reproduction, and stress response.
Pituitary adenomas (tumors) arise from the pituitary gland and are by far the most common growth associated with the gland; they account for 15% of primary brain tumors and are the third most common intracranial tumor after meningiomas and gliomas.
The great majority (over 90%) of pituitary adenomas are benign slow-growing tumors, approximately 5-10% are somewhat more aggressive (atypical) and less than 1% qualify as pituitary carcinoma.
From autopsy studies and MRIs of normal individuals, it is known that 10-20% of the general population has a pituitary adenoma. Most of these tumors remain small and do not cause significant harm or symptoms; however many do progress and grow to cause hormonal and neurological problems.
Pituitary adenomas can be classified based on their size and hormone-producing activity. Microadenomas are small tumors that are less than 1 centimeter in size, while macroadenomas are larger tumors that are more than 1 centimeter in size. Some pituitary tumors can also produce excess hormones, leading to hormonal imbalances and associated symptoms.
Types of Pituitary Adenomas
Pituitary adenomas can be categorized based on their size, behavior, and the hormones they produce. The main types of pituitary adenomas include the following:
Adenomas that make excess hormones (endocrine-active adenomas) include the following main types:
- Prolactinomas: Tumors that produce excessive prolactin hormone.
- Growth hormone-secreting adenomas: Tumors that produce excessive growth hormone.
- ACTH-secreting adenomas: Tumors that produce excessive adrenocorticotropic hormone.
Endocrine-inactive or non-functioning adenomas do not produce excessive hormones but may cause symptoms due to their size or location.
- Acromegaly
- Cushing’s Disease
- Endocrine In-Active Adenoma
- Prolactinoma
- Thyrotropinoma
- Pituitary Apoplexy
- Recurrent Residual Adenoma
Who is Affected?
Pituitary adenomas affect about 1 in 1,000 people, and most are benign and treatable. Pituitary adenomas are among the most common types of benign brain tumors, accounting for about 10–15% of all intracranial tumors. They can occur at any age, but are most often diagnosed in adults between 30 and 60 years old.
Both men and women are affected, though some types of pituitary adenomas—such as prolactin-secreting tumors (prolactinomas)—are more common in women. Rarely, pituitary adenomas may occur as part of a genetic syndrome, such as Multiple Endocrine Neoplasia type 1 (MEN1) or Carney complex.
Because these tumors can grow slowly and cause subtle symptoms, many people are diagnosed only after experiencing hormonal changes, vision problems, or headaches that prompt further evaluation.
Pituitary Adenoma Symptoms & Causes
Pituitary adenomas can cause a range of symptoms depending on their type, size, and the hormones they produce. Common symptoms may include headaches, vision problems, fatigue, weight gain or loss, menstrual irregularities, decreased libido, and infertility. Pituitary adenomas may cause problems because of hormonal hyper-secretion.The impact on hormone production can lead to various endocrine disorders, affecting growth, reproduction, metabolism, and other bodily functions. In some cases, pituitary adenomas may also lead to excessive thirst or urination, high blood pressure, or mood changes.
Symptoms
The three most common hormonally active adenomas are prolactinomas, GH-secreting tumors causing acromegaly, and ACTH-secreting tumors causing Cushing’s disease. Thyroid stimulating hormone (TSH) tumors are relatively rare.
Hypopituitarism typically occurs only in larger tumors (macroadenomas) and results from compression and damage to the normal pituitary gland from the enlarging adenoma. Manifestations may include:
- Hypogonadism – sexual dysfunction, loss of libido, and impotence
- Hypothyroidism – fatigue, weakness, weight gain, coarse dry hair and dry skin, cold intolerance, depression
- Adrenal insufficiency – fatigue, weakness, loss of appetite, dizziness, nausea and vomiting
- Growth failure – in children and adolescents
- Hyperprolactinemia – due to “stalk effect”. This is seen in diseases within or near the pituitary gland and stalk. Interfering with the delivery of dopamine, a neuron-transmitter, from the hypothalamus to the prolactin secreting cells of the pituitary gland), which can result in hypogonadism and its associated problems. Rarely posterior pituitary gland damage occurs with diabetes insipidus, which is caused by the inability of the kidneys to conserve water, leading to frequent urination and thirst.
Larger pituitary macroadenomas often cause loss of visual acuity or peripheral vision (termed bitemporal hemianopsia) from pressure on the optic nerves and optic chiasm which is directly above the pituitary gland. Larger macroadenomas especially those that have hemorrhaged (apoplexy) may also cause double vision.
Patients with macroadenomas often have frontal, forehead and temporal area headaches. Pituitary adenoma removal often results in headache resolution.
Pituitary apoplexy develops over hours to several days from hemorrhage and/or infarction of pituitary adenoma (typically a macroadenoma or a Rathke’s cleft cyst).Symptoms may include:
- Headache
- Nausea
- Visual loss
- Double vision
- Confusion
Most patients have undiagnosed hormone insufficiency prior to the apoplectic event. Pituitary apoplexy is best confirmed by MRI. A head CT will also show areas of bleeding or a mass in the sella in the majority of cases. Other conditions that can mimic pituitary apoplexy are a ruptured aneurysm, meningitis, a stroke, intracerebral hemorrhage and migraine headache.
The treatment for most patients with pituitary apoplexy is urgent endoscopic endonasal surgery and intravenous administration of the stress hormone cortisol.
Causes
The exact cause of pituitary adenomas is not fully understood, but genetic factors and hormonal imbalances are believed to play a role. In some cases, these pituitary tumors are associated with rare inherited conditions such as multiple endocrine neoplasia type 1 (MEN1) or Carney complex.
Most pituitary adenomas are sporadic and not inherited, with familial pituitary tumors being uncommon. Multiple Endocrine Neoplasia (MEN) type 1 accounts for less than 5% of all pituitary adenomas. MEN1 is an autosomal dominant disorder characterized by the development of multiple tumors, often involving the pituitary gland, pancreas, and parathyroid glands. Approximately 25% of patients with MEN1 will develop a pituitary adenoma.
When to See a Doctor
If you have a family history of endocrine disorders (such as MEN1) or have been diagnosed with hormonal imbalances, it’s important to discuss your risk with a specialist. Early diagnosis and treatment of pituitary adenomas can prevent complications and help preserve vision, hormone balance, and overall health. You should seek medical evaluation if you experience unexplained symptoms that could be related to a pituitary tumor, such as:
- Persistent headaches that don’t improve with usual treatments.
- Vision changes, including blurred or double vision, or loss of peripheral vision.
- Unexplained hormonal changes, such as irregular menstrual cycles, infertility, decreased libido, or unexplained weight gain or loss.
- Symptoms of hormone overproduction, like rapid weight changes, unusual hair growth, or breast discharge (galactorrhea).
- Fatigue, weakness, or mood changes that are new or worsening.
Pituitary Adenoma Diagnosis
Diagnosing pituitary adenomas involves a comprehensive evaluation, including medical history review, physical examination, hormone level testing, and imaging studies such as MRI or CT scans. Our team of specialists utilizes advanced diagnostic techniques to accurately identify and classify pituitary tumors, enabling personalized treatment plans.
Pituitary Adenoma Treatment & Outcomes
Treatment Options
The treatment options for pituitary adenomas depend on several factors, including the tumor type, size, symptoms, and the patient’s overall health. Treatment modalities may include:
- Medication: Certain pituitary adenomas can be effectively managed with medication to regulate hormone levels and control tumor growth.
- For some hormone-producing (functioning) tumors:
- Prolactinomas often respond well to dopamine agonists (e.g., cabergoline,bromocriptine), which can shrink the tumor and normalize prolactin levels.
- Other hormone-secreting tumors may be managed with medications, when surgery isn’t possible, sometimes as a bridge before surgery, or to treat residual or recurrent disease.
- For some hormone-producing (functioning) tumors:
- Surgery: Surgical intervention may be recommended for larger or hormone-secreting tumors. At Pacific Neuroscience Institute, we specialize in minimally invasive endoscopic endonasal surgery, which offers excellent outcomes with reduced risks and faster recovery.
- Radiation therapy: In some cases, radiation therapy may be used to target and shrink pituitary tumors.
Surgical removal via the endoscopic endonasal approach is the treatment of choice for most patients with asymptomatic pituitary adenoma (with the exception of prolactinomas).
Given major technical advances over the last two decades in high-definition endoscopy, surgical navigation techniques and more effective skull base closure methods, pituitary surgery is safer than ever in experienced hands.
Patient Outcomes
With advances in minimally invasive pituitary surgery and personalized medical therapies, most patients with pituitary adenomas experience excellent outcomes. Many tumors can be effectively treated with endoscopic transsphenoidal surgery, often resulting in symptom relief, restored hormone balance, and preserved vision.
For patients who require ongoing hormone replacement therapy or medical management, regular follow-up with an endocrinologist helps maintain stable hormone levels and prevent complications.
At Pacific Neuroscience Institute, our team has performed thousands of endonasal surgeries, achieving high rates of tumor control with a low risk of complications. We work closely with each patient to ensure the best possible functional and quality-of-life outcomes.
Managing A Pituitary Adenoma
Living with a pituitary adenoma often requires ongoing care and monitoring to maintain your health and prevent complications. Even after treatment, regular follow-up visits with your care team are essential to track hormone levels, vision changes, and overall pituitary function.
At Pacific Neuroscience Institute, our multidisciplinary team of neurosurgeons, endocrinologists, and specialists provides personalized long-term care for patients with pituitary adenomas. With comprehensive follow-up plans, we help you manage your condition effectively and maintain a good quality of life.
Management may include:
Routine Imaging (MRI Scans)
To monitor for tumor recurrence or growth.
Hormone Testing and Replacement
If your adenoma affects hormone production, your endocrinologist may prescribe medications or hormone replacement therapy.
Symptom Management
Addressing headaches, vision problems, or other related symptoms as needed.
Lifestyle Adjustments
Maintaining a balanced diet, managing stress, and following your doctor’s recommendations for exercise and sleep can support overall wellness.
Meet our Expert Specialists & Surgeons
Pituitary tumors and related hormonal disorders are complex in their diagnosis and treatment and warrant a team approach of experienced specialists to achieve optimal outcomes. Our highly experienced experts work closely together on your behalf. From diagnosis to treatment, as well as education and support, we are here for you.
Experience Compassionate, Expert Care
At the Pacific Pituitary Disorders Center, we have one of the world’s largest experiences in endoscopic endonasal transsphenoidal surgery for all types of pituitary adenomas including acromegaly, Cushing’s disease, prolactinomas, non-functional adenomas, pituitary apoplexy and residual or recurrent adenomas.
PNI neurosurgeons and ENT surgeons use a fully endoscopic endonasal approach for all patients presenting with pituitary adenomas, with the median hospital length stay of just one day. By incorporating leading-edge technology and instrumentation with proven surgical experience of over 2,000 endonasal surgeries, our pituitary tumor specialists make pituitary surgery safer, less invasive and more effective leading to the best possible outcomes.
Learn More About a Pituitary Adenoma
Yes. Most pituitary adenomas are benign (noncancerous) and highly treatable. With proper treatment—whether surgery, medications, or hormone therapy—many people go on to live full, normal lives. Regular follow-up with a specialist is important to monitor hormone levels and overall health.
Diagnosis usually involves a combination of hormone blood tests, detailed MRI scans of the brain, and a thorough evaluation by an endocrinologist or neurosurgeon. In some cases, vision tests may also be performed to check for pressure on the optic nerves.
Technically, yes. A pituitary adenoma is a tumor located in the pituitary gland, which sits at the base of the brain. However, most pituitary adenomas are benign and grow slowly, making them very different from malignant brain tumors.
Depending on their size and hormone activity, pituitary adenomas can cause hormonal imbalances (leading to weight changes, menstrual irregularities, or fatigue), vision problems, and headaches. Some tumors don’t produce hormones (nonfunctioning adenomas), while others may secrete excess hormones, such as prolactin, growth hormone, or ACTH, causing specific symptoms.
Symptoms vary but may include persistent headaches, vision changes (like blurred or double vision), unexplained fatigue, mood changes, or hormonal symptoms such as changes in weight, libido, or menstrual cycles. Some people may not notice symptoms until the tumor grows large enough to affect surrounding structures.
Most people with a pituitary adenoma have a normal life expectancy, especially with early diagnosis and proper treatment. Endoscopic transsphenoidal surgery and medical management have excellent long-term outcomes, allowing patients to live healthy, active lives.
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At Pacific Neuroscience Institute, we bring together world-renowned neurosurgeons, endocrinologists, and skull base specialists to treat pituitary adenomas and other pituitary disorders. We use state-of-the-art imaging, minimally invasive endoscopic surgery, and advanced medical therapies to provide personalized care for every patient.