Testing for Pituitary Disorders

The pituitary gland is responsible for regulating hormonal production in the human body. When the gland begins to secrete too much or too little, it often leads to a set of symptoms associated with pituitary disorders. In some cases, the condition involves the presence of a pituitary tumor, which presses against nearby tissues.

The endocrine system is composed of multiple functional and well-integrated parts, including the pituitary gland. Several glands within the human body are interlinked via the endocrine system. These glands produce a variety of hormones to help balance and regulate the body’s natural processes.

This gland is located at the bottom of the brain and behind the sinus cavity. It also sits below the hypothalamus, which is responsible for sending important messages to other parts of the nervous system while regulating the body’s processes. This includes sending hormones designed to start and/or stop the pituitary gland. Once initiated, the pituitary gland begins to release its hormones to other glands, which increases the production of other hormones throughout the endocrine system.

In its basic layout, the pituitary is composed of two parts – the front (anterior) and the back (posterior). Both parts are responsible for different hormones.

  • Anterior (Front): With the anterior pituitary, it’s responsible for secreting GH (growth hormone), TSH (thyroid-stimulating hormone), ACTH (Adrenocorticotrophic hormone), FSH (follicle-stimulating hormone), Prolactin, and LH (luteinizing hormone). These hormones offer a long list of organic benefits, including increased muscle mass, stress regulation, blood sugar levels, bone growth, metabolic rate, sexual characteristics, and fertility. This includes targeting specific tissues in the human body, such as the ovaries for women, testicles for men, thyroid glands, and adrenal glands.
  • Posterior (Back): With the posterior pituitary, it’s responsible for storing ADH (antidiuretic hormone) and oxytocin from the hypothalamus. The antidiuretic hormone helps regulate the kidney’s water output to ensure the body’s water levels remain balanced while oxytocin is responsible for regulating the uterus and its contractions during the birthing process for women while also playing a role during breastfeeding (releasing milk).

It’s important to note that pituitary disorders encompass several different hormones leading to a unique set of symptoms for everyone.

Causes of Pituitary Disorders

When a tumor begins to grow in the area, this can bring along with several medical concerns. The average tumor is diagnosed as a pituitary adenoma (benign), but this can still lead to significant hormonal production by the pituitary gland when it’s active. As a result, this hampers other glands in the endocrine system while restricting blood flow to the surrounding tissues. Optic nerves and/or blood vessels near the tumor can become compromised due to their positioning. Once the tumor begins to press against the surrounding tissues, it will lead to symptoms such as vision problems (loss of vision), headaches, weakness, seizures, fatigue, and other relevant symptoms associated with hormone production.

Additional causes can include:

  • Head Trauma
  • Genetic Conditions (From Birth)
  • Genetic Mutations
  • A Malignant Tumor
  • Reduced Blood Supply to the Pituitary Gland
  • Radiation Treatment
  • Excess Iron (i.e., Blood Transfusions/Hemochromatosis)
  • Unknown Health Condition

Examples of Pituitary Disorders

  • Pituitary Tumors

This type of tumor can cause a variety of symptoms, including too much or too little hormone production. In most cases, the tumor will be benign but can cause symptoms such as headaches, visual problems, and other similar problems as it grows. Due to the added growth, this gland can press against surrounding tissues leading to increased hormone production in some areas and reduced hormone production in others.

  • Growth Hormone Deficiency

This is seen in children and can lead to issues involving delayed growth. For adults, the symptoms can include general fatigue, muscular weakness, obesity, and/or reduced bone mass.

  • Hypopituitarism

This can include trauma, tumors, infections, sarcoidosis, autoimmune concerns, decreased pituitary blood supply, radiation, side effects of pituitary surgery, or the removal of a pituitary gland. Due to these reasons, the body doesn’t gain access to enough pituitary hormone production to stay healthy.

  • Hyperprolactinemia

In this case, the pituitary tumor begins to release prolactin and/or suppresses the secretion of prolactin. This can lead to symptoms involving a lack of breast milk for feeding mothers, too much breast milk (outside pregnancy), low libido, lack of menstrual periods, and erectile dysfunction.

  • Empty Sella Syndrome

This involves the sella, which is a small part of the skull (hollow) where the pituitary is situated. It includes a specialized membrane called the sellae located on top of the pituitary as protection. If something causes this membrane to burst or open, it can lead to a unique MRI scan where the socket appears empty through imaging. Therefore, the condition is called Empty Sella Syndrome by medical experts and can often be associated with radiation therapy or tumors.

  • Craniopharyngioma

This is often seen in young children and teenagers but can also show up in adults over the age of 50. In general, the condition is benign but can press against the pituitary leading to headaches, delayed growth, hypopituitarism, and vision issues.

Rare Pituitary Disorders

  • Acromegaly and Gigantism

This is when the growth hormone production skyrockets because of adenoma (benign tumor). The condition usually occurs in childhood and is linked with gigantism (excessive bone growth), causing children to grow taller than the average adult. This is known as acromegaly as the bone thickens, leading to larger hands, coarsened facial features, headaches, larger feet, sleep apnea, fatigue, sweating, hypertension, colon cancer, and/or diabetes mellitus.

  • Adrenal Insufficiency

This is a rare disorder triggered by pituitary dysfunction. When the hormone ACTH (adrenocorticotropic hormone) depletes, it can often be a sign of adrenal insufficiency. ACTH is responsible for acting as a pituitary messenger. This includes sending messages to the adrenal cortex for it to release cortisol. When the ACTH level drops, it can often be linked to pituitary damage or a pituitary tumor. This leads to a drop in cortisol production, which reduces the amount of aldosterone and cortisone in the body. These hormones are responsible for regulating the body’s blood pressure and metabolism.

  • Cushing Disease

This disorder encompasses specific symptoms associated with excess ACTH caused by the pituitary tumor. When there’s excess ACTH, this leads to hyperactive adrenal glands releasing too much cortisol. Due to the additional cortisol, it can lead to a long list of symptoms including a larger face, obesity (torso), thinner arms, thinner legs, muscular weaknesses, high blood sugar, pink streaks (Abdomen), osteoporosis, and high blood pressure.

  • Diabetes insipidus

This includes a reduction in ADH production via the hypothalamus. The kidneys don’t retain enough water causing the individual to feel thirsty while having to frequent the bathroom often (dilute urination).

  • Nelson Syndrome

This disorder occurs when the adrenal glands have been removed from the human body as a treatment option. The tumor begins to actively produce ACTH while hampering the pituitary hormones. This can lead to symptoms involving skin darkening as the MSH (melanocyte-stimulating hormone) levels rise.

  • Multiple Endocrine Neoplasia Type 1 (MEN1)

This genetic mutation can increase the likelihood of developing tumors close to the pituitary and other similar endocrine glands.

  • Kallman Syndrome

This is a genetic condition due to a deficiency in GnRH (gonadotropin-releasing hormone). This can create a reduction in LH and FSH production while halting a child’s puberty and hampering their ability to smell.

  • Pituitary Infarction

This is often cited as a leading cause of bleeding near a benign pituitary tumor. It occurs once the surrounding tissues have been damaged (hypopituitarism).

  • Sheehan Syndrome

This is a rare condition that occurs after childbirth. It takes place due to excessive bleeding during birth, causing the pituitary gland to lose function. This is noted as a pituitary infarction.

Tests

Comprehensive lab testing can determine the presence of too much or too little hormones. These tests can also pinpoint specific pituitary disorders, their severity, and what type of treatment is best for the individual. With cases of inherited conditions, the risk of a pituitary disorder is seen across all ages and demands constant checkups.

It’s recommended to seek scheduled testing to compare hormonal measurements at different ages. This can help diagnose fluctuations in TSH (thyroid-stimulating hormone) along with additional hormones produced by the endocrine system such as Thyroxine (Thyroid Gland Hormone T4).

Tests can assess the following hormones:

LH and FSH

Prolactin Cortisol and ACTH

Free T4 (Thyroxine) and TSH IGF-1 and GH

Regular test results may include:

  • Constant TSH Levels
  • Varying Cortisol Levels
  • Cyclical LH and FSH Levels (Menstrual Cycle Only)
  • Increased Prolactin Production (During Breastfeeding for Women or Periods of Stress)

These variations in each test necessitate regular testing to pinpoint specific trends in the hormonal levels. This can help determine whether a person has excess or deficient hormones. It can also account for medicine-related suppression or production.