The pituitary gland is a tiny organ that plays an enormous role in hormone regulation. When a tumor develops, its impact on pituitary function can have far-reaching consequences throughout the body. Identifying the type of pituitary tumor is crucial to planning an effective treatment.
Centers for Neurosurgery, Spine & Orthopedics (CNSO) is New Jersey’s most comprehensive brain and spine center. Learn more about the different types of pituitary tumors and how each of them affects hormones.
Pituitary Tumors at a Glance
- Pituitary tumors are tumors that develop in the pituitary gland.
- Some pituitary tumors are functioning, meaning they produce hormones. Functioning (also called functional) pituitary tumors overproduce active hormones that interfere with bodily functions. These symptoms typically lead to the diagnosis of a functioning pituitary tumor.
- Most pituitary tumors are non-functioning tumors, which do not produce active hormones. These tumors typically cause symptoms by compressing the pituitary gland, causing loss of hormone production and secretion, which can also adversely affect bodily functions.
- Types of functioning pituitary tumors are classified by the hormone they secrete, with different types causing different symptoms and health complications.
- Survival rates for pituitary tumors are very high, though long-term hormone therapy may be necessary to manage endocrine disorders after treatment.
What Are Pituitary Tumors?
Pituitary tumors are tumors that develop in the pituitary gland. This almond-sized organ is located at the base of the brain. It releases several important hormones, which are chemicals that carry messages to different parts of the body. They tell organs how to behave to keep various functions coordinated. The pituitary gland also tells multiple other endocrine glands when to release their hormones.
Non-Functioning vs. Functioning Pituitary Tumors
Pituitary tumors are divided into two broad categories depending on their behavior. Tumors that do not produce hormones are considered non-functioning pituitary tumors. Their symptoms are caused by the tumor pressing against nearby structures in the brain. Patients may experience:
- Vision changes or loss
- Headaches
- Loss of hormone function
- Fatigue
- Dizziness
- Decreased sexual function
Tumors that do produce hormones are considered functioning pituitary tumors. They have similar symptoms to non-functioning tumors. They also create additional issues caused by hormonal imbalances. When too much of any hormone is released, the systems it controls will start to malfunction. This leads to widespread complications that present an additional challenge for treatment.
Types of Functioning Pituitary Tumors
Functioning pituitary tumors are further classified by the type of hormone they produce. The pituitary gland releases four primary hormones. Accordingly, there is a pituitary tumor type to correspond with each hormone:
Prolactinoma
Prolactinomas produce prolactin, a hormone that typically increases after a woman gives birth. Prolactin stimulates the mammary glands for milk production. Prolactinomas cause an increase in this hormone for both sexes, regardless of whether the patient has recently been pregnant. Their symptoms include:
- Excess breast milk production
- Nipple discharge
- Enlargement of breasts, even in men
- A low sex drive
- Infertility or a low sperm count
- Irregular menstrual cycles
- Sexual or erectile dysfunction
In the long term, prolactinomas can cause muscle underdevelopment, brittle bones (osteoporosis), irritability, and persistent tiredness or fatigue.
Growth Hormone-Secreting Tumors
Growth hormone-secreting tumors produce growth hormone, which regulates how the body metabolizes sugar and fat and promotes cell growth. It also regulates physical growth and development. Growth hormone-secreting tumors cause acromegaly or gigantism, depending on the age at which they form:
- Acromegaly: The patient develops an abnormally large face, hands, feet, or heart. It occurs when tumors develop in adults whose growth plates have fused.
- Gigantism: In addition to acromegaly, the patient also has an excessively tall stature. It occurs when tumors develop in children whose growth plates have not fused.
Patients with acromegaly or gigantism also experience joint pain, excessive sweating, and the risk of early heart failure due to an enlarged heart.
Adrenocorticotropic Hormone (ACTH)-Secreting Tumors
ACTH-secreting tumors produce cortisol, a hormone that increases with sleep-wake cycles and stress. It performs several vital functions, including regulating metabolism, maintaining blood pressure, and fighting infection. ACTH-secreting tumors cause high cortisol levels, leading to symptoms such as:
- Weight gain
- Slowed healing
- Thin skin that bruises easily
- Severe acne
- High blood pressure
- Sleeplessness
- Extreme tiredness
- Anxiety or irritability
- Vulnerability to infection
Extended periods of high cortisol can cause a set of physical changes known as Cushing’s syndrome. Signifiers of Cushing’s syndrome include:
- Facial roundness
- Weight gain in the abdomen
- Thin arms and legs
- A fatty pad between the shoulders called a “buffalo hump”
- Pink or purple stretch marks
- Diabetes
Cushing’s syndrome has several potential causes, including ACTH-secreting pituitary tumors. When it is caused by a tumor, the syndrome is instead called Cushing’s disease.
TSH-Secreting Tumors
TSH-secreting tumors produce thyroid-stimulating hormone (TSH). This hormone is responsible for regulating thyroid function. Too much of it causes hyperthyroidism, or an overly active thyroid. Symptoms of hyperthyroidism include:
- Unintentional weight loss
- A fast, irregular, or pounding heartbeat
- Nervousness, anxiety, and irritability
- Increased hunger
- Tremors in the hands and fingers
- Excessive sweating
- Increased heat sensitivity
- Changed menstrual cycles
- More frequent bowel movements
- Goiter, or a swelling at the base of the neck
- Difficulty sleeping
- Extreme and persistent tiredness
- Dry, brittle hair
TSH-secreting tumors are rare. They often go undetected, as physicians typically treat patients for an overactive thyroid before looking for a pituitary tumor. In these cases, the tumor is only identified if treatment is ineffective or when other symptoms develop.
Microadenomas vs. Macroadenomas
The final system of tumor classification is by size. Microadenomas are under 10 millimeters wide. They are often asymptomatic unless they are functioning. Many microadenomas are found incidentally when a magnetic resonance imaging (MRI) scan is performed for an unrelated condition. Macroadenomas, meanwhile, are over 10 millimeters wide. Their large size makes them more likely to cause serious symptoms.
Treatment Options for Pituitary Tumors
Treatments for pituitary tumors depend on the tumor’s type and size. They include:
- Observation: If the tumor is small and non-functioning, direct intervention may not be necessary. Physicians simply observe the tumor for signs of growth.
- Surgery: Surgical removal is first-line treatment of almost all symptomatic pituitary tumors and macroadenomas, except for prolactinomas. Surgery performed through the sinuses is considered minimally invasive and does not leave a visible scar.
- Medication: Hormone imbalances are dangerous by themselves. Medications may be used to control how much of a hormone, especially prolactin, is made by the tumor. Treatment generally focuses on replacing a hormone that is low and is not a primary treatment for the tumor. The exception is prolactinomas, where the medical treatment not only decreases the prolactin level but also tends to shrink and primarily treat the tumor.
- Radiation therapy: External radiation therapy or gamma knife treatment can be used, typically for recurrences or portions of the tumor that cannot be safely removed, or in patients who can’t tolerate surgery due to age or underlying medical condition.
Large pituitary tumors may damage the pituitary gland. In this case, hormone replacement therapy may be necessary to manage a long-term endocrine disorder after the tumor is removed. Patients make lifestyle changes and meet regularly with endocrinology specialists to ensure their well-being.
Find Expert Pituitary Tumors Treatment Near You in New Jersey
Centers for Neurosurgery, Spine & Orthopedics neurosurgeons and brain tumor team are leading experts in the treatment of all types of pituitary tumors and are at locations near you across New Jersey. CNSO’s award-winning team includes neurosurgeons, orthopedic spine surgeons, interventional pain management physicians, physiatrists, rehabilitation specialists, and certified physical therapists, ensuring that patients receive the appropriate care. Contact CNSO today to learn more or schedule an appointment.
Frequently Asked Questions About Pituitary Tumors
What are the most common types of pituitary tumors?
The most common types of pituitary tumors are non-functioning pituitary tumors.
Is a pituitary microadenoma dangerous?
Pituitary microadenomas are not usually dangerous, especially if they do not produce hormones. They should still be monitored, however, in case the tumor continues to grow or causes new symptoms.
Can pituitary tumors cause permanent endocrine disorders?
Pituitary tumors can cause permanent endocrine disorders, especially if they cannot be removed surgically or if they grow large enough to damage the pituitary gland. Endocrine disorders can be managed with hormone therapy and lifestyle adjustments.
What is the survival rate for pituitary tumors?
The five-year survival rate for pituitary tumors is over 97%, and most patients can return to their normal lives after treatment.
