Is Your Pituitary Gland Affected by a Tumor? Understanding Pituitary Adenoma

Do you sometimes get frequent headaches for no apparent reason? Or do you feel like your eyesight is a bit weak, like you can't see things coming from the sides clearly? Or perhaps you're experiencing discomfort due to some changes in your body's hormones? Sometimes, the reason behind these issues could be a small tumor developing in your pituitary gland. Today, let's talk in detail about pituitary adenoma. Don't worry, this is not cancer.

What is a Pituitary Adenoma?

Simply put, a pituitary adenoma is a benign tumor that develops in your pituitary gland. It does not spread to other parts of the body like cancer; that is the most important thing. However, as this adenoma grows, it can compress surrounding nerves, blood vessels, and other structures. That's when various symptoms begin to appear.

So, What is the Pituitary Gland?

Imagine a tiny gland, about the size of a pea, located behind your nose and connected to the base of your brain, specifically the hypothalamus. That is what is called the pituitary gland. Despite its small size, it performs many vital functions in our body.

This gland has two main parts:

• The Anterior Lobe
• The Posterior Lobe

Both of these parts produce and release various types of hormones into the bloodstream. Hormones are like chemical messengers that control and coordinate various functions in our body. They travel through the blood to deliver necessary messages to our organs, muscles, and other tissues.

Some of the important hormones produced by the pituitary gland include:

• Adrenocorticotropic hormone (ACTH or Corticotropin)
• Antidiuretic hormone (ADH or Vasopressin)
• Follicle-stimulating hormone (FSH)
• Growth hormone (GH)
• Luteinizing hormone (LH)
• Oxytocin (Oxytocin)
• Prolactin
• Thyroid-stimulating hormone (TSH)

Not only that, but the pituitary gland also sends "signals" to other endocrine glands in our body to produce hormones. So, you can understand that if there is a problem with the pituitary gland, such as an adenoma, it can affect the function of one hormone or several hormones.

How are These Adenomas Classified?

Doctors classify pituitary adenomas mainly in two ways.

1. Based on hormone production:

• Functioning (Secreting) Adenomas: These types of adenomas produce one or more additional pituitary hormones. As a result, various symptoms and conditions can arise depending on the excess hormone produced.
• Nonfunctioning (Non-secreting) Adenomas: These adenomas do not produce hormones. However, if they grow large, they can cause symptoms by compressing surrounding brain structures or nerves. This type of adenoma is often the most commonly encountered by doctors.

2. Based on size:

• Microadenomas: These are tumors smaller than 10 millimeters (i.e., 1 centimeter).
• Macroadenomas: These are tumors larger than 10 millimeters. Macroadenomas are about twice as common as microadenomas. Furthermore, these large tumors increase the likelihood of one or more pituitary hormone levels decreasing (a condition called Hypopituitarism).

Is This Considered a Brain Tumor?

Actually, the pituitary gland is a structure belonging to the endocrine system, and technically not part of the brain itself. It is connected to the base of the brain. However, doctors classify pituitary adenomas as brain tumors. Approximately 10% of all primary brain tumors are pituitary adenomas.

Who is More Susceptible to These, and How Common Are They?

Pituitary adenomas can occur at any age. However, they are most commonly seen in people in their 30s and 40s. Additionally, women have a slightly higher chance of developing these adenomas than men.

In terms of prevalence, pituitary adenomas account for 10% to 15% of all intracranial tumors. Statistics show that approximately 77 people per 100,000 have this condition. However, researchers believe that a larger percentage of the population, possibly up to 20%, might develop an adenoma at some point in their lives. Often, especially with microadenomas, people experience no symptoms and the condition goes undiagnosed.

What are the Symptoms of a Pituitary Adenoma?

The symptoms of a pituitary adenoma can vary greatly from person to person. This primarily depends on several factors:

• Whether the adenoma has grown large enough to damage the pituitary gland itself or cause a (Mass Effect) by compressing surrounding structures.
• Whether it is a functioning (hormone-secreting) adenoma, and if so, the symptoms will depend on the type of hormone it produces.

Mass Effect Symptoms Caused by Macroadenomas (Large Tumors)

Large adenomas (Macroadenomas) primarily cause symptoms due to the compression of surrounding tissues.

Imagine a large item in a small room, where other things get squeezed due to lack of space – it's similar to that.

• Vision Problems:

About 40% to 60% of individuals with a large pituitary adenoma experience impaired vision (blurry vision, double vision). This happens because the adenoma compresses the optic chiasm, the junction connecting the eyes and the brain. As a result, peripheral vision can be especially affected. It's like a horse wearing blinkers, where the side vision is lost.

• Headaches:

Many people with pituitary adenomas complain of frequent headaches. This can be due to the tumor compressing surrounding tissues. However, headaches are a common symptom with many possible causes, so it could also be due to other reasons.

• Hormonal Deficiency:

Large adenomas (Macroadenomas) can damage pituitary gland tissues, leading to a decrease in the production of one or more pituitary hormones. This condition is called Hypopituitarism. The symptoms vary depending on which hormone is deficient.

• When LH and FSH hormones are low (Hypogonadism): Estrogen levels in women and Testosterone levels in men decrease. This can lead to excessive sweating in women, vaginal dryness, and in men, erectile dysfunction, reduced facial and body hair growth. Both sexes may experience mood changes, decreased libido, and extreme fatigue.
• When TSH hormone is low (Hypothyroidism): The amount of hormones produced by the thyroid gland decreases. This can lead to symptoms such as fatigue, constipation, decreased heart rate, dry skin, swelling in the limbs, and weakened reflexes.
• When ACTH hormone is low (Adrenal Insufficiency): The body's production of Cortisol hormone decreases. This can cause symptoms such as Low Blood Pressure, nausea, vomiting, abdominal pain, and loss of appetite.
• When GH (Growth Hormone) is low (Growth Hormone Deficiency): Symptoms vary with age. In adults, this can lead to fatigue and reduced muscle mass.

Symptoms Caused by Functioning Adenomas

Since functioning adenomas secrete one or more additional hormones, various symptoms and conditions arise corresponding to each hormone.

• Prolactinomas (Lactotroph Adenomas):

These adenomas produce excessive Prolactin hormone. This condition is called Hyperprolactinemia. About 4 out of 10 pituitary tumors are of this type. This is the most common type of pituitary adenoma. When prolactin levels are high, the normal functioning of the reproductive system in both men and women can be disrupted.

• Infertility in both males and females.
• Galactorrhea (breast discharge resembling milk), even when not pregnant.

• Somatotroph Adenomas:

These adenomas produce excessive Growth Hormone (Somatotropin). About 2 out of 10 pituitary tumors are of this type. The symptoms that occur vary with age.

• In adults: A rare but serious condition called Acromegaly develops. In this condition, bones and tissues in the body grow abnormally. Over time, hands, feet, and the head become larger, and facial features change. It also affects Blood Sugar control, and the heart muscle can enlarge.
• In children and adolescents: A condition called Gigantism (giantism) develops. Due to excessive growth hormone, they grow to an abnormally tall height.

• Corticotroph Adenomas:

These adenomas produce excessive ACTH (Adrenocorticotropic hormone). About 1 out of 10 pituitary tumors are of this type. ACTH stimulates the adrenal glands to produce more steroid hormones like Cortisol. This leads to Cushing’s Syndrome (excessive Cortisol condition).

• High Blood Pressure.
• Muscle weakness.
• Easy bruising.
• Purple Stretch Marks (more than 1 cm wide) on the abdomen.
• Osteoporosis (thinning of bones).
• Compression Fractures.
• Type 2 Diabetes Mellitus.

• Thyrotroph Adenomas:

These adenomas produce excessive TSH (Thyroid-stimulating hormone). These are extremely rare. TSH stimulates the thyroid gland to produce more thyroid hormones. This leads to Hyperthyroidism (overactive thyroid condition), accelerating the body's metabolism.

• Increased heart rate.
• Unexplained weight loss.
• Frequent loose bowel movements.
• Sweating.
• Trembling hands.
• Anxiety.

Important: There can be many other causes for Hyperthyroidism. A pituitary adenoma is a very rare cause for it.

• Gonadotroph Adenomas:

These adenomas produce excessive Gonadotropins (i.e., LH and FSH hormones). These are also extremely rare.

• This can lead to irregular menstrual cycles, Ovarian Hyperstimulation Syndrome (OHSS) and similar conditions in women.
• In men, it can cause enlarged testicles, deepening of the voice, hair loss (at the temples), and rapid facial hair growth.
• In children, Precocious Puberty may occur.

What Causes Pituitary Adenomas?

Scientists still don't know the exact cause of these adenomas.

However, some adenomas have been found to be associated with random changes (Mutations) in the DNA of our cells. These genetic changes cause pituitary gland cells to grow rapidly and uncontrollably, forming a Mass (tumor). These genetic changes can sometimes be inherited from parents (familial) or occur spontaneously as new random mutations.

Additionally, pituitary adenomas can be associated with some rare genetic conditions. A few examples include:

• Multiple Endocrine Neoplasia type 1 (MEN1)
• Multiple Endocrine Neoplasia type 4 (MEN4)
• Carney complex
• X-LAG syndrome
• Succinate dehydrogenase-related familial pituitary adenoma
• Neurofibromatosis type 1
• Von Hippel–Lindau syndrome

Individuals with such genetic conditions have an increased risk of developing a pituitary adenoma. However, it's important to remember that these adenomas can also develop in people without any genetic predisposition.

How Do Doctors Diagnose This Condition (Diagnosis)?

The process of diagnosing a pituitary adenoma varies depending on factors such as the type of adenoma you have and whether it is causing symptoms.

Often, in someone with a functioning adenoma (hormone-secreting), the condition (e.g., Cushing's Syndrome, Acromegaly) resulting from the hormonal imbalance is initially identified based on symptoms. Only then, while investigating the cause, is the adenoma discovered. This is because many conditions caused by excessive hormones can have other reasons besides pituitary adenomas. The same applies to Hypopituitarism (pituitary hormone deficiency).

Sometimes, a pituitary adenoma may be discovered incidentally during a head Imaging Test (scan) performed for another medical condition. Many such incidentally found adenomas are usually small and nonfunctioning.

What Tests are Performed for This?

If your doctor suspects you might have a pituitary adenoma, they will thoroughly review your symptoms and medical history and perform a physical examination. Additionally, they may recommend one or more of the following tests:

• Blood Tests: Depending on your symptoms, blood tests may be ordered to check the levels of various pituitary hormones.
• Imaging Tests: An MRI (Magnetic Resonance Imaging) scan or a CT (Computed Tomography) scan of the head can provide clear images of the structures inside your head. These tests can confirm the presence of a pituitary adenoma and determine its size. MRI is the most suitable and sensitive test for this purpose.
• Eye Exam: If you have any vision problems, your doctor may ask you to undergo a Visual Field Test. This test is important because large pituitary adenomas can compress the optic nerves connecting the eyes to the brain, leading to vision problems.

How are Pituitary Adenomas Treated?

There are three main treatment methods for pituitary adenomas: Surgery, Medication, and Radiation Therapy. Sometimes, one or more of these methods may be used in combination. Since each person's adenoma and condition are unique, you and your medical team can work together to determine the most suitable treatment plan for you.

Surgical Removal of Adenomas (Surgery)

If you have an adenoma that causes hormonal imbalance or affects vision, your doctor will most likely recommend surgery to remove all or part of the adenoma. Depending on the size of the adenoma and the severity of symptoms, more than one surgery may be necessary.

Surgeons often use a surgical method called Transsphenoidal Surgery for this purpose. This involves accessing the pituitary gland through the nose and the Sphenoid Sinus (an empty space behind the nasal cavity, below the brain) to remove the adenoma. Approximately 95% of pituitary tumors are removed using this method, which is a relatively safe procedure.

However, if the adenoma is too large to be removed through the nose or is located in a complex area, the surgeon may need to perform Transcranial Surgery by opening the skull. This method is rarely used for pituitary adenomas.

Treatment with Medication

Some types of pituitary adenomas, especially Prolactinomas, can be controlled and shrunk with medication.

For individuals with Prolactinomas (which are the most common type), first-line treatment for several months involves Dopamine Agonist medications, such as Cabergoline (Dostinex®) or Bromocriptine (Cycloset®).

The good news is that in about 80% of cases, these medications shrink the prolactinoma, and prolactin hormone levels return to normal.

If medication is ineffective or if it's another type of adenoma, the doctor may recommend surgery.

Radiation Therapy

In Radiation Therapy, high-energy X-rays are used to destroy adenoma cells, causing the tumor to shrink or stop further growth. For pituitary adenomas, a specialized and highly precise radiation therapy method called Stereotactic Radiosurgery (e.g., Gamma Knife®) is used. In this procedure, multiple radiation beams are precisely directed only at the adenoma from various angles, minimizing damage to surrounding healthy tissues. This method is used for remaining parts after surgery or in cases where surgery is not feasible.

What are the Side Effects of Treatment?

Like any medical treatment, treatments for pituitary adenomas can have certain side effects.

• After surgery and/or Radiation Therapy, approximately 60% of individuals who had pituitary adenomas may develop Hypopituitarism (decreased production of one or more pituitary hormones). Although this is a lifelong condition, a normal life can be lived by taking Hormone Replacement Medications for the deficient hormones.
• Possible surgical complications:
  • Bleeding.
  • Cerebrospinal Fluid (CSF) leakage (watery discharge from the nose).
  • Meningitis (an infection of the brain's protective membranes).
  • Diabetes Insipidus (excessive diluted urine output and extreme thirst due to low antidiuretic hormone).
• Common side effects of Dopamine Agonist medications for Prolactinomas: Headaches, nausea, vomiting, dizziness, and sometimes Compulsive Behavior.
• Possible side effects of Radiation Therapy:
  • Pituitary hormone deficiency (may develop over time).
  • Impaired Fertility.
  • Vision loss and damage to brain tissue (very rare).
  • Development of another tumor in the same area many years after treatment (very rare).

Can These Adenomas Be Prevented?

Unfortunately, there is nothing specific you can do to prevent a pituitary adenoma from developing. Most of the time, these occur randomly. However, as mentioned earlier, they can be associated with certain rare genetic conditions.

If a close family member (sibling or parent) has such a genetic condition, you can discuss with a doctor about undergoing genetic counseling and Genetic Testing to determine if you also carry that genetic condition. If such a condition is present, doctors can frequently monitor you and initiate treatment early if an adenoma develops.

What is the Prognosis for This Condition?

The prognosis of a pituitary adenoma, meaning the outlook for recovery and future health, depends on the size, type of adenoma, and the treatment you receive.

The good news is that in most cases, when the adenoma is completely removed or controlled through treatment, patients can resume a full, healthy life.

In some cases, treatment might lead to reduced hormone production by the pituitary gland. If this happens, you may need to take Hormone Replacement Medications for the deficient hormones throughout your life.

Adenomas can sometimes Recur. This means that after some time, you may need to undergo treatment again. Statistics show that about 18% of individuals with nonfunctioning adenomas and about 25% of those with prolactinomas may require re-treatment in the future. Therefore, maintaining regular contact with your doctor and undergoing scheduled check-ups is very important.

Can You Live with a Pituitary Adenoma?

Yes, it is possible. If a pituitary adenoma is small and causes no symptoms, you can live normally with it. In fact, many people only discover they have an adenoma incidentally during a head Scan for another reason. However, if the adenoma continues to grow or starts causing symptoms, treatment will definitely be necessary.

If you have a large and/or functioning (hormone-secreting) pituitary adenoma, treatment is definitely required. This is because some pituitary adenomas can significantly impact your health and quality of life.

What are the Complications if Left Untreated?

If left untreated, some pituitary adenomas – especially large adenomas (Macroadenomas) and functioning (secreting) adenomas – can lead to serious health problems. These health issues largely depend on the type of hormone secreted by the adenoma (which we discussed earlier in the "Symptoms" section).

One of the extremely rare but highly dangerous complications that can arise from untreated pituitary adenomas is Pituitary Apoplexy. This is a Medical Emergency where bleeding occurs within or around the pituitary gland.

Pituitary Apoplexy most commonly occurs due to bleeding into a pituitary adenoma. The sudden enlargement of the tumor damages the pituitary gland. The larger the adenoma, the higher the risk of Pituitary Apoplexy.

The symptoms of Pituitary Apoplexy usually appear very quickly and can be life-threatening. The main symptoms are:

• An extremely severe headache (like no headache ever experienced before).
• Due to paralysis of eye muscles, double vision or inability to lift an eyelid.
• Loss of peripheral vision or complete vision loss in one or both eyes.
• Low Blood Pressure, nausea, and vomiting due to Acute Adrenal Insufficiency.
• Personality changes (e.g., confusion) due to sudden narrowing of the Anterior Cerebral Artery in the brain.

Pituitary Apoplexy is a rare condition, but it is extremely serious. If you experience one or more of these symptoms, call an emergency medical service immediately (like 911) or have someone take you to the nearest hospital's emergency department as quickly as possible.

When Should You See a Doctor?

• If you have any vision problems (blurriness, double vision, reduced peripheral vision) and/or persistent or recurrent headaches (especially in the frontal area), consult a doctor about it.
• If you have already been diagnosed with a pituitary adenoma, you will need to regularly visit your doctor to monitor the adenoma's condition and ensure the treatment is working effectively.

Finally, Remember These Key Points

It's very normal to feel scared and anxious when you find out you have a Tumor. However, the best news about pituitary adenomas is that they are mostly (over 99%) benign tumors and in most cases, very good results can be achieved through treatment.

Remember, your doctor is your partner in achieving your best health. Therefore, never hesitate to inform your doctor about any symptoms, discomfort, or questions you have regarding your treatment. With correct information and timely treatment, you can certainly manage this condition successfully.