Second Opinion on Pituitary diseases

Pituitary gland definition, location and function 

Hypophysis (or the pituitary gland) is an endocrine gland about the size of a cherry pit and weighing less than one gram. It lies in a depression on the superior surface of the sphenoid bone, right below the brain. Above it is the hypothalamus, an area containing cells, that regulate the body's neuroendocrine activity.

In general, this part of the brain plays a crucial role in hormone-dependent processes and metabolism. In particular, it is here that the substances controlling sexual function and thyroid activity are produced.

Pituitary gland disorders

Diseases of this gland are relatively rare. They can be associated with an abnormal production of hormones or with an increase in the size of the gland due to an inflammation or a tumor. In this case, there is a compression of nearby tissues, which leads to grave consequences; for example, impaired vision.

Adenoma

The most common issue (about 80 percent of cases) is pituitary adenoma. Although these masses are benign, they result in an uncontrolled secretion of hormones (e.g. - prolactin, which causes menstrual disorders in women and loss of libido and erectile dysfunction in men).

Pituitary adenoma can be distinguished in two ways, depending on the answer to the following questions:

Small adenomas that do not secret hormones do not need treatment. In this case, regular monitoring is sufficient.

If the adenoma is larger and/or endocrine-active, therapy is necessary. Depending on the case, this can be surgery, drugs or radiotherapy.

Cushing disease

If a benign tumor located in the anterior lobe of the gland produces excessive amounts of adrenocorticotropic hormone (ACTH), the adrenal cortex begins to produce too much cortisol. This condition is called Cushing's disease.

Typical manifestations of the disease are:

• weight gain: legs and arms tend to remain slim, while the face and cheeks look full;
• bruising and impaired wound healing due to increased vascular fragility;
• excess hair in a male pattern (= hirsutism) in women and acne in both sexes;
• irregularity or cessation of menses in women;
• reduced muscle strength (myopathy), especially in the muscles of the buttocks and thighs;
• increased anxiety and depressive thoughts, mood swings.

Possible consequences are diabetes mellitus, increased blood pressure accompanied by depletion of potassium stores in the body. Low levels of potassium in the blood can lead to poor blood circulation and irregular heart rhythm. Excess cortisol also has an adverse effect on the bones and cause loss of bone mass (osteoporosis).

The main treatment for a tumor causing Cushing's disease is its surgical removal. As a rule, minimally invasive, so-called transsphenoidal (performed through the nose) surgery is performed. If it fails to achieve a complete cure, radiation therapy may be considered. Often hormone production does not decrease until several years after radiation therapy, but the method can be successful in the long term.

If none of the above treatments can cope with excessive hormone production, doctors sometimes have to resort to the removal of both adrenal glands. In this case, lifelong hormone replacement therapy is required to compensate for the now completely absent adrenal function.

Acromegaly

A pituitary tumor can uncontrollably secrete too much growth hormone (somatotropin hormone, STH). This leads to the clinical picture of acromegaly, a disease characterized by abnormal growth of the limbs (hands and feet) and protruding body parts such as the chin, ears, and nose.

It usually takes about eight years from the first symptoms to diagnosis. Physical changes are slight at first, as the characteristic clinical pattern develops gradually, without dramatic changes in appearance. Therefore, the disease is often diagnosed accidentally, for example, when changing doctors.

In very rare exceptional cases, acromegaly may have a cause other than tumors in the pituitary gland (in less than 1% of patients).

If acromegaly is suspected, the screening test is the determination of insulin-like growth factor-I (IGF-I), which is produced in the liver under the influence of growth hormone and contributes to many of its functions.

Sugar (glucose) administration in healthy people leads to suppression of STH secretion. If after that its values exceed 1 mcg/L, the diagnosis is confirmed. In this case, the production of other pituitary hormones (which rule the function of the ovaries, adrenal glands and thyroid gland) is checked. To identify the most likely cause (tumor), as well as to determine its size and relationship to surrounding structures, especially to the so-called optic chiasm (the part of the brain where the optic nerves are located), an MRI scan is performed. If the mass has grown beyond the sella turcica, an eye examination is necessary.

The main treatment option for acromegaly is complete removal of the tumor, if possible, with preservation or restoration of the remaining functions of the gland (so-called selective adenomectomy). Success depends on the size of the tumor (i.e., how early it was detected) and the experience of the neurosurgeon (preferably, the surgery should be performed by a specialist who does at least 30 such procedures per year).

If the therapeutic goal is not achieved after surgery, drug therapy or radiation therapy may be used as second-line therapy. Drug therapy may include:

• dopamine agonists (which inhibit the release of growth hormone);
• somatostatin analogs;
• a new therapeutic drug that is a growth hormone antagonist that blocks the action of STH in tissues (called a receptor antagonist).

Radiotherapy is considered if the above measures fail or the tumor grows again. It reduces the concentration of growth hormone by about 10% per year. If the initial concentration is high, the STH level remains elevated for up to 10 years or more. Drug therapy is necessary to overcome this period. The most important side effect is the occurrence of pituitary hypofunction even years after therapy.

Inflammation

Extremely rarely, inflammation of the pituitary gland (hypophysitis) can develop, causing headaches and visual disturbances.

It is usually caused by a protective reaction of the immune system (autoimmune disease).

However, hypophysitis can also be provoked by taking medications or occur as a complication of other diseases, including tuberculosis, sarcoidosis, inflammatory vascular diseases and vasculitis.

Signs of inflammatory processes in the gland are headaches, visual disturbances, weight gain. Slightly more than half of patients suffer from urinary retention and, as a consequence, greater thirst (the so-called diabetes insipidus). 

Hormonal deficiency associated with inflammatory lesions of the anterior lobe is also common. This leads to menstrual irregularities in women, and adrenal insufficiency may develop in both sexes.

To suggest a successful therapeutic strategy, a doctor must have a good understanding of this complex and rare disease. In the absence of severe symptoms and signs of optic chiasm lesions, the reasonable options are regular monitoring and hormone replacement. In addition to hormone therapy, glucocorticoids should be used, especially in cases of very severe headaches. Such therapy almost always results in significant improvement. If the pain is too bad, or there is a threat of visual field deficit, pituitary surgery is performed.

Second opinion

In the case of diseases that are uncommon, do not have clear clinical signs, have a chronic course and are likely to develop complications, seeking a second opinion is more than worthwhile. The low incidence of many endocrine disorders associated with the pituitary gland leads to the fact that not each endocrinologist at a nearby health care facility may prove to have sufficient competence to make an accurate diagnosis and recommend the correct treatment.

The availability of quite a large number of medications developed for this kind of diseases is good news for patients, but for doctors it means the need to keep up to date with recent trends, clinical trials and current guidelines. Therefore, before you agree to a proposed course of therapy, and moreover, if the drugs you are taking fail to bring the desired effect, it's worth seeking another opinion. Especially since these days you don't even need to leave home to obtain one, since you can visit your doctor online.