Understanding Pituitary Brain Cancer

Pituitary brain cancer is a term that can be a bit confusing because the vast majority of tumors that start in the pituitary gland are actually benign, meaning they are not cancerous. These non-cancerous tumors are called pituitary adenomas. True pituitary cancer, where the tumor is malignant and can spread to other parts of the body, is very rare.

However, even though most pituitary tumors are not cancerous, they can still cause significant health problems by affecting the pituitary gland‘s normal function and putting pressure on nearby structures in the part of the brain.

This article aims to provide a clear and easy-to-understand explanation of what pituitary tumors are, why the term “pituitary brain cancer” might be used, the different types of pituitary tumors, the symptoms they can cause, how they are diagnosed, the available treatment options, and what the outlook is for people affected by these conditions.

What is the Pituitary Gland and Why is it Important?

To understand pituitary tumors, it’s helpful to know about the pituitary gland itself. This small, pea-sized gland is located at the base of the brain, just behind the eyes. Often called the “master gland,” it plays a crucial role in regulating many of the body’s essential functions by producing and releasing various pituitary hormones. These hormones control other endocrine glands, which in turn produce their own hormones that affect everything from growth and metabolism to reproduction and stress response.

Some of the key pituitary hormones include:

Growth hormone (GH): Essential for growth, especially during childhood, and also plays a role in metabolism in adults.
Prolactin: Primarily responsible for milk production in women after childbirth.
Adrenocorticotropic hormone (ACTH): Stimulates the adrenal glands to produce cortisol, a hormone involved in stress response and metabolism.
Thyroid-stimulating hormone (TSH): Stimulates the thyroid gland to produce thyroid hormones, which regulate metabolism (thyroid stimulating hormone).
Luteinizing hormone (LH) and follicle-stimulating hormone (FSH): Control sexual development and reproduction.
Antidiuretic hormone (ADH): Regulates water balance in the body.
Oxytocin: Involved in social bonding, reproduction, and childbirth.

Because the pituitary gland controls so many vital functions through these pituitary hormones, any disruption to its normal activity, whether from a benign tumor or, rarely, a cancerous one, can lead to a wide range of health problems affecting different parts of the body.

Why the Term “Pituitary Brain Cancer” Can Be Misleading

As mentioned earlier, the vast majority of tumors that start in the pituitary gland are pituitary adenomas, which are pituitary tumors are benign. The term “pituitary brain cancer” is not technically accurate for these common adenomas because they are not cancerous and typically do not spread to other parts of the body outside of the brain area.

However, the term might be used by some people or in certain contexts for a few reasons:

Location: Pituitary tumors are located in a critical part of the brain and can exert significant pressure on nearby structures, such as the optic nerves (affecting vision) and the hypothalamus (regulating body temperature, hunger, and sleep). This pressure can sometimes lead to serious neurological symptoms, making it seem like a brain cancer in its impact.
Rare Pituitary Carcinomas: In extremely rare cases, a pituitary tumor can be malignant, meaning it is a true cancer that can invade surrounding tissues and spread to other parts of the body. These are called pituitary carcinomas. In such situations, the term “pituitary brain cancer” would be more fitting.
Impact on Health: Even benign pituitary adenomas can cause significant and life-altering health problems due to the overproduction or underproduction of crucial pituitary hormones. These hormonal imbalances can affect various parts of the body, leading to conditions like acromegaly (excess growth hormone), Cushing’s disease (excess cortisol), or hypopituitarism (deficiency of one or more pituitary hormones).

Therefore, while most pituitary tumors are not technically “cancer,” their location and potential impact on health can sometimes lead to the use of the term “pituitary brain cancer” in a broader sense to describe any significant tumor affecting the pituitary gland and surrounding brain structures.

Types of Pituitary Tumors

When we talk about the types of pituitary tumors, we primarily refer to pituitary adenomas, which are classified based on:

Size:Microadenomas: These are small, less than 1 centimeter (about the size of a pea).
Macroadenomas: These are larger, 1 centimeter or more. Larger tumors are more likely to put pressure on nearby structures like the optic nerves.
Hormone Production (Functional vs. Non-functional):Functional Adenomas: These tumors produce and release excessive amounts of one or more pituitary hormones, leading to specific hormonal syndromes. Examples include:
Growth hormone-secreting adenomas (causing acromegaly in adults and gigantism in children).
Prolactinomas (secreting prolactin, causing menstrual changes and milk production in women, and sexual dysfunction in men).
ACTH-secreting adenomas (causing Cushing’s disease).
Thyroid stimulating hormone (TSH)-secreting adenomas (leading to hyperthyroidism).
LH and FSH-secreting adenomas (can cause various reproductive issues).
Non-functional Adenomas: These tumors do not produce significant amounts of hormones. Their symptoms usually arise from their size and the pressure they exert on the pituitary gland and surrounding structures like the optic nerves.

True pituitary carcinomas are extremely rare and are characterized by their ability to spread to other parts of the body outside the brain area.

Symptoms of Pituitary Tumors

The symptoms of a pituitary tumor can vary greatly depending on the types of pituitary tumor (functional or non-functional), its size, and the structures it is putting pressure on.

Symptoms related to hormone levels from functional adenomas can include:

Growth hormone excess: Enlarged hands, feet, and facial features (acromegaly); excessive growth in children (gigantism); joint pain; high blood pressure; diabetes.
Prolactin excess: Irregular or absent menstrual periods; breast milk production in women who are not pregnant or breastfeeding; infertility; decreased libido and erectile dysfunction in men.
ACTH excess: Weight gain; fatty deposits on the face and upper back; thin skin; easy bruising; high blood pressure; diabetes.
TSH excess: Symptoms of hyperthyroidism such as rapid heartbeat, weight loss, anxiety, and tremors.
LH and FSH excess: Irregular periods in women; infertility; rarely, increased testosterone in men.

Symptoms caused by the size of the tumor and putting pressure on surrounding structures, especially from macroadenomas and non-functional adenomas, can include:

Headaches.
Vision problems: Blurred vision, double vision, loss of peripheral vision due to pressure on the optic nerves.
Nausea and vomiting.
Dizziness.
Fatigue.
Symptoms of hypopituitarism (if the tumor damages the normal pituitary gland), such as fatigue, weakness, decreased libido, and menstrual changes.

In the rare case of pituitary carcinoma, symptoms might also include those related to the spread of the cancer to other parts of the body.

Diagnosis of Pituitary Tumors

Diagnosing a pituitary tumor typically involves a combination of:

Medical History and Physical Exam: The doctor will ask about your symptoms and medical history and perform a general physical exam.
Hormone Level Testing: Blood tests are crucial to measure the levels of various pituitary hormones and hormones produced by other endocrine glands controlled by the pituitary. This helps determine if the tumor is functional and which hormones are affected.
Imaging Tests:Magnetic Resonance Imaging (MRI): An imaging test using powerful magnets and radio waves to create detailed pictures of the pituitary gland and surrounding brain tissue. MRI is usually the preferred imaging test for diagnosing pituitary tumors as it provides the best visualization of the soft tissues.
Computed Tomography (CT) Scan: Another imaging test that uses X-rays to create cross-sectional images of the brain. While MRI is preferred, a CT scan might be used in some cases or if MRI is not possible.
Visual Field Testing: If the tumor is putting pressure on the optic nerves, a visual field test can assess if there is any loss of peripheral vision.

Treatment Options for Pituitary Tumors

The treatment options for pituitary tumors depend on the types of pituitary tumor (functional or non-functional), its size, symptoms, and the patient’s overall health.

Medication

For some functional adenomas, especially prolactinomas, medication is often the first-line treatment. Drugs called dopamine agonists can effectively shrink the tumor and lower prolactin hormone levels. Medications can also be used to manage the symptoms of hormone excess in other functional adenomas, such as those causing Cushing’s disease or acromegaly, often in conjunction with other treatments.

Surgery

Surgery to remove the tumor is a common treatment for many pituitary adenomas, especially macroadenomas that are putting pressure on the optic nerves or other structures, and for functional adenomas that are not well-controlled with medication. The most common surgical approaches include:

Transsphenoidal Surgery: This is the most common method and involves reaching the pituitary gland through the nasal passages and sphenoid sinus (a hollow space behind the nose). It is a minimally invasive procedure with a high success rate for many tumors.
Craniotomy: This involves opening the skull to access the tumor. It is typically reserved for larger or more complex tumors that cannot be safely removed through the transsphenoidal approach.

Radiation Therapy

Radiation therapy uses high-energy rays to destroy tumor cells. It may be used in several situations:

After surgery: To treat any remaining tumor cells, especially in cases of incompletely removed tumors or more aggressive adenomas.
As primary treatment: For tumors that cannot be surgically removed due to their location or the patient’s overall health.
For recurrent tumors: If a pituitary tumor grows back after previous treatment.

Types of radiation therapy used for pituitary tumors include:

External Beam Radiation Therapy: Delivers radiation from a machine outside the body.
Stereotactic Radiosurgery: A highly precise form of radiation therapy that delivers a single, high dose of radiation to a small target area, minimizing damage to surrounding brain tissue like the optic nerves. Techniques like Gamma Knife or CyberKnife are used.

Clinical Trials

For patients with aggressive or recurrent pituitary tumors, participation in clinical trials exploring new treatment options may be considered.

Long-Term Outlook and Management

The long term outlook for people with pituitary adenomas is generally good, especially for microadenomas and those that can be completely surgically removed. However, regular follow-up is essential to monitor for recurrence and to manage any hormone levels that may still be abnormal.

For macroadenomas and more aggressive tumors, the long term management may involve a combination of surgery, radiation, and medication. Lifelong hormone replacement therapy may be necessary if the pituitary gland has been damaged by the tumor or its treatment, leading to hypopituitarism.

In the rare cases of pituitary carcinoma, the prognosis is more guarded, and treatment focuses on controlling the growth and spread of the cancer.

While the term “pituitary brain cancer” often refers to benign pituitary adenomas located in a critical part of the brain, it’s important to understand that true pituitary cancer (carcinoma) is very rare.

The majority of pituitary tumors are pituitary tumors are benign but can still cause significant health problems due to hormonal imbalances and pressure on surrounding structures like the optic nerves.

Understanding the different types of pituitary tumors, their symptoms, diagnosis using imaging test like MRI and CT scans, and the various treatment options including medication, surgery to remove the tumor, and radiation therapy is crucial for effective management and improving the long term outlook for individuals affected by these conditions. Ongoing research and clinical trials continue to explore new ways to treat and manage pituitary tumors.

Learn how you can make a difference by visiting our Donate page.

If you’d like to contribute your time and skills, please visit our Volunteer page.

For those in need of financial assistance during their cancer journey, you can find more information on our Financial Assistance page.