Involutive changes in the pituitary gland. Diseases of the pituitary gland and hypothalamic-pituitary system

Description:

Hormones that affect the functioning of all organs and systems enter the blood from special endocrine glands, which are united into a single endocrine system. These are the adrenal glands, thyroid and parathyroid glands, ovaries (in women), testes and testes (in men), pancreas, hypothalamus and pituitary gland. Perhaps there is no more hierarchical and disciplined system in the body than the endocrine one.

At the pinnacle of power is the pituitary gland, a small gland rarely larger than the size of a child's little fingernail. The pituitary gland is located in the brain (at its very center) and tightly controls the work of most endocrine glands, secreting special hormones that control the production of other hormones. For example, the pituitary gland releases thyroid-stimulating hormone (TSH) into the blood, which causes the thyroid gland to create thyroxine and triiodothyronine. Some pituitary hormones have a direct effect, for example, somatotropic hormone (STH), which is responsible for growth processes and physical development child.

A deficiency or excess of pituitary hormones inevitably leads to serious illnesses.

Symptoms:

Lack of pituitary hormones leads to:

      * To a secondary deficiency of hormones of other endocrine glands, for example to secondary hypothyroidism - deficiency of thyroid hormones.
      * In addition, the lack of pituitary hormones themselves causes severe physical disorders. Thus, deficiency of somatotropic hormone (GH) in childhood leads to dwarfism.
      * - with a lack of antidiuretic hormone (ADH is produced in the hypothalamus, then enters the pituitary gland, from where it is released into the blood)
      * - a lack of all pituitary hormones - in children it can manifest itself as delayed sexual development, and in adults - sexual disorders. In general, hypopituitarism leads to severe metabolic disorders that affect all body systems.

An excess of pituitary hormones gives a clear clinical picture, and the manifestations of the disease differ greatly depending on which hormone or which hormones exceed the norm.

With an excess of pituitary hormones:

      * High levels of prolactin (hyperprolactinemia) in women are manifested by menstrual irregularities, infertility, lactation (swelling of the mammary glands and secretion of milk). In men it leads to decreased libido and impotence.
      * Excess growth hormone (GH) has given the world giants. If the disease begins at an early age, then it occurs; if in adulthood, it occurs. According to the Guinness Book of Records, the tallest man was Robert Pershing Wadlow, born in 1918 in the USA. His height was 272 centimeters (arm span 288 centimeters). However, according to the domestic book of records Divo, the tallest in world history was Russian citizen Fedor Makhov. His height was 2 meters 85 centimeters and his weight was 182 kilograms. With acromegaly, the patient's hands and feet thicken, facial features become large, and internal organs become enlarged. This is accompanied by cardiac dysfunction and neurological disorders.
      * An increase in the level of adrenocorticotropic hormone (ACTH) leads to Itsenko-Cushing's disease. This serious disease manifests itself as osteoporosis, increased blood pressure, development, mental disorders. The disease is accompanied by characteristic changes in appearance: weight loss in the legs and arms, obesity in the abdomen, shoulders, and face.

Causes:

To understand the causes of pituitary gland diseases, it is necessary to remember that it is part of the brain. The optic nerves pass over it, and on the sides there are large cerebral vessels and oculomotor nerves.

The cause of excess pituitary hormones in most cases is a tumor of the pituitary gland itself - an adenoma. At the same time, the level of the hormone or hormones that the adenoma cells produce increases, while the level of all other hormones can significantly decrease due to compression of the remaining part of the pituitary gland. A growing adenoma is also dangerous because it compresses nearby optic nerves, blood vessels and brain structures. Almost all patients with adenoma have headaches, and visual disturbances are common.

The causes of pituitary hormone deficiency can be:

      * blood supply defects,
      * hemorrhage,
      * congenital underdevelopment of the pituitary gland,
      * or ,
      * compression of the pituitary gland by a tumor,
      * ,
      * some medications,
      * irradiation,
      * surgical intervention.

Treatment:

For treatment the following is prescribed:

Treatment of pituitary gland diseases is aimed at normalizing the level of hormones in the blood, and in the case of adenoma, reducing the pressure of the tumor on the surrounding brain structures. If there is a lack of pituitary hormones, hormone replacement therapy is used: the person is given medications that are analogues of the necessary hormones. This treatment often lasts for life. Fortunately, pituitary tumors are extremely rarely malignant. However, their treatment is a difficult task for the doctor.

The following methods and their combinations are used in the treatment of pituitary tumors:

      * drug therapy;
      * surgical treatment - tumor removal;
      * methods .

- a group of benign, less often malignant, neoplasms of the anterior lobe (adenohypophysis) or posterior lobe (neurohypophysis) of the gland. Pituitary tumors, according to statistics, make up about 15% of neoplasms of intracranial localization. They are diagnosed equally often in both sexes, usually between the ages of 30 and 40. The vast majority of pituitary tumors are adenomas, which are divided into several types depending on size and hormonal activity. Symptoms of a pituitary tumor are a combination of signs of a large intracerebral process and hormonal disorders. Diagnosis of a pituitary tumor is carried out by conducting a number of clinical and hormonal studies, angiography and MRI of the brain.

General information

The pituitary gland is an endocrine gland that performs a regulatory and coordinating function in relation to some other endocrine glands. The pituitary gland is located in the fossa of the sella turcica of the sphenoid bone of the skull, and is anatomically and functionally connected with the part of the brain - the hypothalamus. Together with the hypothalamus, the pituitary gland forms a single neuroendocrine system that ensures the constancy of the body's homeostasis.

The pituitary gland has two lobes: the anterior - adenohypophysis and the posterior - neurohypophysis. The hormones of the anterior lobe produced by the adenohypophysis are: prolactin, which stimulates milk secretion; somatotropic hormone that affects the growth of the body through the regulation of protein metabolism; thyroid-stimulating hormone, which stimulates metabolic processes in the thyroid gland; ACTH, which regulates adrenal function; gonadotropic hormones that affect the development and function of the gonads. The neurohypophysis produces oxytocin, which stimulates uterine contractility, and antidiuretic hormone, which regulates the process of water reabsorption in the kidney tubules.

Abnormal proliferation of gland cells leads to the formation of tumors of the anterior or posterior pituitary gland and disruption of hormonal balance. Sometimes meningiomas—tumors of the meninges—grow into the area of the pituitary gland; less often, the gland is affected by metastatic screenings of malignant neoplasms of other localizations.

Causes of pituitary tumors

The reliable causes of the development of pituitary tumors have not been fully studied, although it is known that some types of tumors may be genetically determined.

Factors predisposing to the development of pituitary tumors include neuroinfections, chronic sinusitis, traumatic brain injury, hormonal changes (including due to long-term use of hormonal drugs), and adverse effects on the fetus during pregnancy.

Classification of pituitary tumors

Pituitary tumors are classified taking into account their size, anatomical location, endocrine functions, microscopic staining characteristics, etc. Depending on the size of the tumor, microadenomas (less than 10 mm in maximum diameter) and macroadenomas (with a maximum diameter of more than 10 mm) of the pituitary gland are distinguished.

Based on location in the gland, tumors of the adenohypophysis and neurohypophysis are distinguished. Pituitary tumors, according to their topography relative to the sella turcica and its surrounding structures, are endosellar (extending beyond the boundaries of the sella turcica) and intrasellar (located within the sella turcica). Taking into account the histological structure, pituitary tumors are divided into malignant and benign neoplasms (adenomas). Adenomas arise from the glandular tissue of the anterior pituitary gland (adenohypophysis).

According to the functional activity, pituitary tumors are divided into hormonally inactive (“silent”, incidentalomas) and hormonally active adenomas (producing one or another hormone), which occur in 75% of cases. Among the hormonally active tumors of the pituitary gland are:

Somatotropin-producing adenomas:

somatotropic adenoma
somatotropinoma - a tumor of the pituitary gland that synthesizes somatotropin - growth hormone;

Prolactin-secreting adenomas:

prolactin adenoma
prolactinoma – a tumor of the pituitary gland that synthesizes the hormone prolactin;

Adrenocorticotropin-producing adenomas:

corticotropic adenoma
corticotropinoma - a tumor of the pituitary gland that secretes ACTH, stimulating the function of the adrenal cortex;

Thyrotropin-producing adenomas:

thyrotropic adenoma
thyrotropinoma - a tumor of the pituitary gland that secretes thyrotropic hormone, which stimulates the function of the thyroid gland;

Foltropin-producing or lutropin-producing adenomas (gonadotropic). These pituitary tumors secrete gonadotropins, which stimulate the function of the gonads.

Hormone-inactive pituitary tumors and prolactinomas are the most common (in 35% of cases, respectively), somatotropin-producing and ACTH-producing adenomas - in 10-15% of all pituitary tumors, other types of tumors are rare. Based on microscopy characteristics, they distinguish between chromophobe tumors of the pituitary gland (hormonally inactive adenomas), acidophilic tumors (prolactinomas, thyrotropinomas, somatotropinomas) and basophilic tumors (gonadotropinomas, corticotropinomas).

The development of hormonally active pituitary tumors that produce one or more hormones can lead to the development of central hypothyroidism, Cushing's syndrome, acromegaly or gigantism, etc. Damage to hormone-producing cells during adenoma growth can cause a state of hypopituitarism (pituitary insufficiency). In 20% of patients, asymptomatic pituitary tumors are observed, which are detected only at autopsy. The clinical manifestations of pituitary tumors depend on the hypersecretion of a particular hormone, the size and growth rate of the adenoma.

Symptoms of pituitary tumors

As the pituitary tumor grows, symptoms from the endocrine and nervous systems develop. Somatotropin-producing pituitary adenomas lead to acromegaly in adult patients or gigantism if they develop in children. Prolactin-secreting adenomas are characterized by slow growth and present with amenorrhea, gynecomastia and galactorrhea. If such pituitary tumors produce defective prolactin, then clinical manifestations may be absent.

ACTH-producing adenomas stimulate the secretion of hormones from the adrenal cortex and lead to the development of hypercortisolism (Cushing's disease). Typically, such adenomas grow slowly. Thyrotropin-producing adenomas often accompany the course of hypothyroidism (functional thyroid deficiency). They can cause persistent thyrotoxicosis, which is extremely resistant to medical and surgical treatment. Gonadotropic adenomas that synthesize sex hormones lead to the development of gynecomastia and impotence in men, and to menstrual irregularities and uterine bleeding in women.

An increase in the size of the pituitary tumor leads to the development of side effects nervous system. Since the pituitary gland is anatomically adjacent to the optic chiasm, when the size of the adenoma increases to 2 cm in diameter, visual disturbances develop: narrowing of the visual fields, swelling of the optic nerve papillae and its atrophy, leading to a decrease in vision, even blindness.

Pituitary adenomas large sizes cause compression of the cranial nerves, accompanied by symptoms of damage to the nervous system: headaches; double vision, ptosis, nystagmus, limitation of eyeball movements; convulsions; persistent runny nose; dementia and personality changes; increased intracranial pressure; hemorrhages into the pituitary gland with the development of acute cardiovascular failure. When the hypothalamus is involved in the process, episodes of impaired consciousness may occur. Malignant pituitary tumors are extremely rare.

Diagnosis of pituitary tumors

Necessary studies for suspected pituitary tumors include thorough ophthalmological and hormonal examinations, and neuroimaging of the adenoma. Testing urine and blood for hormone levels allows us to determine the type of pituitary tumor and the degree of its activity. An ophthalmological examination includes an assessment of visual acuity and fields, which allows us to judge the involvement of the optic nerves in the process.

Neuroimaging of a pituitary tumor can be done by radiography of the skull and sella turcica, MRI and CT scan of the brain. X-rays can reveal an increase in the size of the sella turcica and erosion of its bottom, as well as an increase in the lower jaw and sinuses, thickening of the skull bones, and widening of the interdental spaces. Using MRI of the brain, it is possible to see pituitary tumors with a diameter of less than 5 mm. Computed tomography confirms the presence of an adenoma and its exact size.

In case of macroadenomas, angiography of cerebral vessels indicates displacement of the carotid artery and makes it possible to differentiate a pituitary tumor from an intracranial aneurysm. Cerebrospinal fluid analysis may reveal elevated levels of proteins.

Treatment of pituitary tumors

Today, in the treatment of pituitary tumors, endocrinology uses surgical, radiation and medicinal methods. For each type of pituitary tumor, there is a specific, most optimal treatment option, which is selected by an endocrinologist and neurosurgeon. Surgical removal of the pituitary tumor is considered the most effective. Depending on the size and location of the adenoma, either its frontal removal through an optical device or resection through the sphenoid bone of the skull is performed. Surgical removal of pituitary tumors is complemented by radiation therapy.

Hormone-inactive microadenomas are treated with radiation therapy. Radiation therapy is indicated in the presence of contraindications to surgical treatment, as well as in elderly patients. In the postoperative period, hormone replacement therapy (cortisone, thyroid or sex hormones) is carried out, and, if necessary, correction of electrolyte metabolism and insulin therapy.

Drugs used include dopamine agonists (cabergoline, bromocriptine), which cause shrinkage of prolactin- and ACTH-secreting pituitary tumors, as well as cyproheptadine, which lowers the level of corticosteroids in patients with Cushing's syndrome. An alternative treatment for pituitary tumors is to freeze a section of pituitary tissue using a probe inserted through the sphenoid bone.

Prognosis for pituitary tumors

The further prognosis for pituitary tumors is largely determined by the size of the adenomas, the possibility of their radical removal and hormonal activity. In patients with prolactinomas and somatotropinomas, complete restoration of hormonal function is observed in a quarter of cases, with adrenocorticotropin-producing adenomas - in 70-80% of cases.

Pituitary macroadenomas larger than 2 cm cannot be completely removed, so they may recur within a 5-year period after surgery.

Internal secretion is impossible without the pituitary gland; it regulates the level of a variety of hormones in the body. And those, in turn, are responsible for the growth of the body, its sexual functions and metabolism. That is, dysfunction of the pituitary gland can lead to very serious consequences.

The pituitary gland is located in the lower part of the brain in the so-called “sella turcica”, has a membrane that separates it from the medulla, and is closely connected to the hypothalamus. Violation of pituitary functions consists not only of an excess of some hormone, but also of its lack. Both situations are equally dangerous for the state of the body, they just manifest themselves in different ways.

The pituitary gland, despite its small sizes(approximately 10 mm long and 6 mm long), produces several types of hormones:

TSH - this hormone stimulates the functions of the thyroid gland, causing it, in turn, to produce a number of its hormones.
ACTH - corticotropin - causes the adrenal glands, which are also part of the endocrine system, to work.
LH and FSH are gonadotropins.
PRL – prolactin.
GH is responsible for human growth.

Thus, it becomes clear that it regulates the functioning of the entire endocrine system, and is an indirect producer of almost all hormones in the human body. The pituitary gland itself is regulated by the hypothalamus.

If there is too much of one or more hormones in the body, this situation is called hyperfunction, and a deficiency is called hypothyroidism. A striking example of hypothyroidism is dwarfism.

Causes of disruption of the normal functioning of the pituitary gland

Disorders, malfunctions of the hormonal functions of the pituitary gland, are usually caused by some reasons; hypothyroidism or hyperfunction itself does not occur:

The main cause of dysfunction of the pituitary gland is various types of tumors that suppress its work. This may be a glioma, meningioma, metastatic tumor, or aneurysm.
Another cause is physical damage to the pituitary gland due to traumatic brain injury.
Damage to the pituitary gland can occur as a result of brain surgery.
He can be harmed by strong gamma radiation, even if he was not directly exposed to it. That is, the peripheral nervous system was irradiated.
The pituitary gland can be damaged by inflammation caused by an infection such as meningitis or encephalitis.
Disruption of the human autoimmune system leads to the destruction of the pituitary gland.
A malfunction of the pituitary gland can be a cerebral hemorrhage or, more simply, a stroke.
Poor blood circulation in the brain leads to necrosis of pituitary gland tissue, which causes disruption of its functioning.

Symptoms of hormonal dysfunction of the pituitary gland

Dysfunction of the pituitary gland manifests itself in different ways, depending on which hormone is missing or, on the contrary, there is an excess of it.

With a deficiency of growth hormone - GH - the symptoms manifest themselves as follows:

The child grows very slowly, or his growth stops altogether.
Bones become strong due to lack of minerals.
Muscle mass decreases.
Hypoglycemia occurs.

With TSH deficiency, the following symptoms occur:

The patient develops chronic fatigue, which is accompanied by apathy.
Ordinary physical activity leaves a person exhausted.
Appetite weakens.
Body weight increases.
Intestinal function is disrupted and constipation occurs.
The heart begins to work at an increased rhythm.
Blood pressure decreases.
The skin becomes dry and thin.
Hair and nails flake, become brittle and dry.
The voice changes timbre, loses its sonority and clarity.
Anemia develops.
There is increased sensitivity to cold.

Inhibition of ACTH leads to the following manifestations:

The function of the adrenal glands is disrupted; they also begin to produce low levels of their hormones.
Fatigue and chronic weakness occur.
The person begins to suffer from constant headaches.
Chronic weakness leads to frequent loss of consciousness.
The melanin content in the skin decreases, which leads to chronic pallor.
Appetite decreases.
Body weight is rapidly decreasing.

Suppression of LH and FSH production leads to:

Irregularity of menstrual cycles in women. Often their complete cessation occurs.
In men, sexual function weakens until it becomes completely ineffective.
The function of conception is impaired.
In the child's body, tertiary sexual characteristics cease to develop - enlarged mammary glands, pubic hair, and the body structure characteristic of a man or woman.

If dysfunction of the pituitary gland has led to a decrease in the production of several or all hormones, then, accordingly, all the symptoms appear at once. In some cases, suppression of pituitary gland function can lead to decreased production of some hormones and increased levels of others.

With hyperfunction of the pituitary gland, one or more hormones may exceed the norm. Hyperfunction is usually associated with tumor growth in or near the pituitary gland. In this case, the symptoms look like this:

Children during their growth period exceed all accepted norms, this is called gigantism.
In some cases, the feet and hands actively grow - acromegaly.
Blood glucose levels are disrupted and diabetes mellitus develops.
In women, the regularity of the menstrual cycle is disrupted.
In men, sexual impotence occurs along with loss of libido.

Diagnosis of hormonal dysfunction of the pituitary gland

Since hormones are synthesized not only in the pituitary gland, but also in the entire endocrine system - the adrenal glands, the thyroid gland, the first step in diagnosis is a laboratory analysis of the level of hormones in the blood. Insufficiency or excess of one or another hormone leads to further diagnostic steps. This may be an ultrasound examination of the adrenal glands or thyroid gland, as well as a computed tomography scan of the pituitary gland itself.

But magnetic resonance imaging can provide the most accurate results; it can detect failures not only in the pituitary gland, but also in the entire endocrine system in one session.

Treatment of hormonal dysfunction of the pituitary gland

Treatment is aimed at eliminating the causes of depression or, conversely, hyperactivity of the pituitary gland in the production of hormones. If the cause is a tumor, it is removed during surgery.

At malignant tumor Radiation therapy is used, during which the tumor is treated with hard gamma radiation. An emergency operation is performed for a stroke; in this case, not only a person’s health, but also a person’s life depends on the speed of its implementation.

If the factors inhibiting the pituitary gland are infectious diseases, then a course of targeted antibiotics is used. For example, with meningitis or encephalitis. In cases where the release of only one type of hormone is suppressed, replacement therapy is given. It consists of taking exactly the hormone that is not produced. So, when the secretion of growth hormone is suppressed, the child takes a recombinant hormone.

When LH and FSH are suppressed, women are prescribed a course of drugs containing estrogen, and men, respectively, testosterone. With ACTH deficiency, the patient takes glucocorticoids. L-thyroxine is replaced by TSH.

Any treatment is individual. The dosage and regimen of medications is determined by the patient’s individual characteristics. As well as his age and general physical condition.

Prevention of hormonal dysfunction of the pituitary gland

Preventing injury or other events that lead to dysfunction of the pituitary gland is quite difficult. As for injuries, you need to be more careful at work and, for example, when driving a car. Of course, it is not possible to completely protect yourself from an accident, but basic compliance with safety rules significantly reduces the risk of brain damage.

Sheehan syndrome
Hemorrhage into the pituitary gland
Injury
Craniopharyngioma
Pituitary tumors

Hormonally inactive

Undifferentiated adenomas
Subtype III

Hormonally active

Prolactinoma
Somatotropinoma
Corticotropinoma
Thyrotropinoma
Gonadotropinoma
Mixed

Sarcoidosis

Isolated deficiency of gonadotropic hormones

Congenital secondary hypogonadism and Kallmann syndrome belong to a group of rare diseases caused by the absence or delay of sexual development due to insufficient secretion of LH and FSH. The underlying neuroendocrine abnormalities are divided into two groups: molecular defects of the gonadotropic cascade leading to isolated secondary hypogonadism, and hypothalamic abnormalities associated with GnRH-secreting neurons or hypoplasia of the olfactory tract in Kallmann syndrome. In some cases there is anosmia. The defect is associated with a disruption in the formation of neurons secreting GnRH in the olfactory placodes of the developing nose, or with a disruption in their migration from the olfactory bulbs to the infundibulum nucleus during embryogenesis. The level of gonadotropic hormones may be normal or reduced, the level of other pituitary hormones remains normal. However, the gonads of patients are not able to synthesize sex hormones. Both disorders are genetic in nature. In patients with secondary hypogonadism, mutations in the GNRH1 and GPR54/KISS1R genes are detected. TLSZ and TACR3 or resistance of pituitary cells to GnRH. The diseases are often, but not always, monogenic syndromes and may be inherited in an autosomal dominant manner. For diagnosis, GnRH is injected intravenously and the stimulated level of gonadotropic hormones is measured. In general, treatment consists of cyclic administration of estrogens and progestogens to promote puberty. When planning pregnancy, GnRH is prescribed in pulse mode through a dispenser or preparations of gonadotropic hormones, which leads to the maturation of follicles and ovulation.

Postpartum pituitary necrosis (Sheehan syndrome)

Sheehan syndrome belongs to the field of emergency endocrinology. At autopsies of women who died between 12 hours and 34 days after birth, necrosis of the adenohypophysis was found in approximately 25% of cases. In almost all cases, the development of pituitary necrosis was preceded by massive bleeding during childbirth, accompanied by a drop in blood pressure and shock. This syndrome appears to occur more often when diabetes mellitus. The pathogenesis of the syndrome remains unknown. Clinically, there is a partial deficiency or complete absence of one or more pituitary hormones, up to apituitarism. Symptoms of adrenal insufficiency (hypotension, nausea, vomiting, drowsiness) or hypothyroidism may appear. The residual function of the pituitary gland can be assessed using provocative tests with thyrotropin-releasing hormone, gonadoliberin, somatoliberin, and corticoliberin.

Hemorrhage into the pituitary gland

Patients complain of severe headache in the retro-orbital region, visual disturbances, changes in the pupils, and impaired consciousness are noted. These symptoms may simulate other neurological diseases, such as basilar artery occlusion, hypertensive crisis, or cavernous sinus thrombosis. An MRI or CT scan reveals hemorrhage in the pituitary gland. Many patients are diagnosed with prolactinoma, and the administration of dopamine receptor stimulants such as bromocriptine, pergolide or cabergoline can stop the process, but surgical decompression may also be required.

Post-traumatic hypopituitarism

Severe traumatic brain injury, such as from car accidents, can damage the pituitary portal system. These patients may exhibit hyperprolactinemia and diabetes insipidus. The most common initial symptoms include hypogonadism, amenorrhea, decreased appetite, weight loss, and galactorrhea.

Extrapituitary tumors

Various tumors can affect the pituitary gland or grow in the area adjacent to the sella turcica. Craniopharyngioma is a slow-growing tumor, its frequency is 1.2-4.6% with two age peaks: in childhood and at the age of 45-60 years. The tumor grows from the stratified squamous epithelium of the remnants of Rathke's pouch; its diameter can reach 8-10 cm; tumor growth can lead to compression of the optic chiasm, hypothalamus and third ventricle. In many cases, craniopharyngioma is localized suprasellar, in 50% of cases it is calcified, which facilitates diagnosis. Craniopharyngioma is hormonally inactive. Patients complain of vomiting, headache, blurred vision, and symptoms of diabetes insipidus. For diagnosis, CT or MRI is used. The basis of treatment is surgical removal of the tumor, although, according to the literature, the tumor is rarely completely removed due to technical difficulties. In cases of incomplete removal, radiation therapy is usually performed after surgery.

Empty sella syndrome

Empty sella syndrome is usually accompanied by hyperprolactinemia, ovulation disorders and galactorrhea. X-rays reveal an enlargement of the pituitary fossa, which confirms two possible reasons of this syndrome:

protrusion of the arachnoid membrane through the sellar diaphragm and
pituitary tumor infarction.

There are no specific treatments for this syndrome; dopamine receptor stimulants are used to reduce hyperprolactinemia and hormonal therapy with combined estrogen-progestogen drugs.

Pituitary tumors

It is estimated that pituitary adenomas occur in 10-23% of the population. At autopsy, inactive pituitary tumors are found in 12% of cases. Pituitary tumors account for 10% of all intracranial neoplasms. However, it is assumed that during a mass X-ray examination, the pathology referred to in the medical literature as “incidentally detected pituitary adenoma” will be diagnosed in 27% of cases.

Hormonally inactive tumors

Some hormonally inactive pituitary tumors deserve attention. Most often these are undifferentiated pituitary adenomas. The tumor grows slowly and hyperprolactinemia may develop, which greatly complicates diagnosis and leads to the wrong choice of treatment. Another type of hormonally inactive tumors, subtype III adenomas, is characterized by rapid aggressive growth. In the literature, this type of tumor is referred to as “invasive adenoma”; it closely resembles meningioma, invades the dura mater and is capable of metastasizing.

Hormone-active pituitary tumors

Prolactinoma

The most common type of hormonally active pituitary tumor in humans is prolactinoma. The prevalence of this tumor in the population ranges from 6-10 to 50 per 100,000. According to an analysis of case histories of 1607 patients receiving drug therapy for hyperprolactinemia, the frequency of prolactinoma in men was 10 per 100,000, in women - 30 per 100,000. Prolactinoma develops due to excessive proliferation of lactotropic cells, which are located mainly in the lateral parts of the pituitary gland. Prolactinoma can grow outward, invading bone structures and the cavernous sinus, or upward, damaging the optic chiasm. Tumors smaller than 10 mm in size are defined as microadenomas, while tumors larger than 10 mm are defined as macroadenomas. The nature of progression of these two types of tumors differs significantly: microadenomas are characterized by a much more benign course than macroadenomas.

Ovulation disorders in patients with pituitary tumors develop on average 5 years before the onset of galactorrhea. In childhood and adolescence, the disease leads to disruption of puberty; Large pituitary tumors are often found in patients who have not had menstruation or had one or two menstrual cycles before developing amenorrhea. In addition to hypogonadism, patients with prolactinomas develop metabolic disorders and decreased bone density, although the risk of fractures is not increased. If prolactinoma is suspected, serum prolactin levels are determined. A level greater than 250 µg/L usually indicates the presence of a tumor, and a level greater than 500 µg/L is a sign of a macroadenoma. However, the absolute level of prolactin cannot serve as a reliable marker of tumor size. Radiologists generally prefer MRI. Visual field testing using the Goldmann perimeter is not advisable for confirmed macroadenoma. In such patients, approximately 68% of cases have upper quadrant bitemporal hemianopsia. Tumors that do not extend beyond the sella turcica do not compress the optic chiasm, so it is pointless to examine the visual fields in these patients.

Treatment of prolactinomas

Currently, drug therapy is considered the method of choice for prolactinomas, and only if it is ineffective or impossible, the issue of surgery or radiation therapy is decided. Tumor recurrence, the likelihood of panhypopituitarism (approximately 10-30% for macroadenomas), complications (rare cases of meningitis, frequent but transient diabetes insipidus, liquorrhea) and the risk of death (albeit small, less than 1%) are the reason for refusal of surgical treatment in the majority sick. Radiation therapy remains a reserve option for dopamine receptor stimulant-resistant cases, as well as for malignant prolactinomas. After radiation therapy, prolactin levels return to normal in about a third of patients, but it takes up to 20 years to achieve this effect. In addition, the use of radiation therapy is limited by side effects such as hypopituitarism, damage to cranial nerves (in rare cases), and the development of secondary tumors.

Patients who choose drug treatment have been treated since the mid-1970s. Dopamine receptor stimulants are prescribed. The first drug in this group was bromocriptine, which binds to both D 1 and D 2 receptors and suppresses the synthesis and secretion of prolactin. The effect on D 1 receptors is associated with the development of arterial hypotension, nausea, and nasal congestion. Another common side effect of the drug is dysphoria. Bromocriptine should be prescribed at night to suppress the nocturnal rise in prolactin production. You need to start with a dose of 1.25 mg and gradually increase it over several weeks. With intravaginal administration, side effects are mitigated, but treatment results are unsatisfactory.

Pergolide and quinagolide are used to treat Parkinson's disease and, rarely, hyperprolactinemia. These drugs belong to ergoline derivatives and are active in doses of 50-100 mcg once a day.

Cabergoline (Dostinex) is a selective D 1 receptor agonist. Currently, cabergoline is recognized as a first-line drug in the treatment of most diseases and conditions accompanied by hyperprolactinemia. The minimum therapeutic dose should reduce prolactin concentrations to normal values. The maximum permissible dose is considered to be the one that the patient can tolerate without serious side effects. In a prospective study of increasing the daily dose of cabergoline, normalization of prolactin levels was achieved in 149 of 150 patients with micro- and macroadenomas of the pituitary gland. In most cases, dosages of 2.5 to 3 mg per week were required to eliminate hyperprolactinemia, but in some cases cabergoline was required at a dose of up to 11 mg per week. The use of high doses of cabergoline has raised concerns due to the effect of valve regurgitation identified in patients with Parkinson's disease receiving the drug at a dose of at least 3 mg per week. However, 6 of 7 studies that analyzed the risk of complications from the valvular apparatus of the heart when using cabergoline in patients with hyperprolactinemia did not reveal a significant increase in the risk of valve pathology. Only one study reported a 57% increase in the incidence of tricuspid regurgitation, although the incidence of this complication also increased significantly in the control group. Although there is no clear evidence of cabergoline's cardiac side effects, monitoring with echocardiography is necessary.

Dopamine receptor stimulants are effective in the vast majority of cases. The possibility of increasing the dose of cabergoline to the maximum tolerated allows one to overcome apparent resistance to therapy. However, in a number of patients, true tumor resistance to dopamine receptor stimulants is observed, which is manifested by the lack of normalization of prolactin levels when prescribing the maximum tolerated dose and the inability to reduce tumor size by 50%. With macroadenomas, resistance is observed more often than with microadenomas (18 and 10%, respectively). Fortunately for gynecologists, this phenomenon is more common in men. The resistance of prolactinoma to different dopamine receptor stimulants is not the same. Thus, in 80% of patients, resistance to bromocriptine can be overcome by prescribing cabergoline. Direct comparisons of tumor size dynamics between bromocriptine and cabergoline have not been made. However, the results various works indicate that bromocriptine reduces tumor size by approximately 50% in 2/3 of patients, while cabergoline leads to its complete disappearance in 90% of patients.

The outcomes of more than 6,000 pregnancies that occurred during the use of bromocriptine were tracked. There was no increase in the incidence of malformations in children, as well as pregnancy complications. A twelve-year prospective study, which summarized the observation of 380 women whose pregnancies occurred while using cabergoline, showed that the number of premature births, pregnancy complications, and malformations in children does not increase compared with the general population. The rate of spontaneous abortion in women who became pregnant while taking cabergoline was about 9% and was lower than in the general population in the United States and Europe (11-15%). Thus, cabergoline, like bromocriptine, can be used in treatment programs for women with infertility.

IN large quantities Studies have shown that prolactinoma does not affect the course of pregnancy. On the other hand, the growth of macroprolactinomas during pregnancy can accelerate significantly. In this regard, in women with macroadenomas, regular examination of visual fields is recommended, and, if they are narrowed, MRI without contrast is performed.

As for radiological diagnostic methods, re-examination in the absence of changes in symptoms should be carried out no more than once every 10 years, since microprolactinomas grow slowly. According to some authors, when treating with dopamine receptor stimulants, repeated use of these methods is not required at all. For macroprolactinomas, repeat CT or MRI is recommended after 6 months of treatment. Some believe that if the tumor has not increased or has decreased to the size of microprolactinoma, the symptoms do not increase, and treatment continues, there is no need for re-examination.

Somatotropinoma

Tumors that secrete GH produce subtle symptoms, and diagnosis is usually made with a delay of up to 6 years. First of all, changes affect the face, hands and feet. Bone growth and soft tissue proliferation are stimulated, which leads to an increase in the size of the nose, lower jaw and brow ridges. Due to the development of carpal tunnel syndrome, paresthesia in the hands may appear due to thickening of the vocal cords. rough voice. Arterial hypertension occurs in a quarter of patients, obesity - in half, myocardial hypertrophy, and an increase in the size of the liver and kidneys are noted. In diagnosis, assessment of the level of growth hormone or a pathological response to a glucose load is important. Treatment options may include surgical removal of the tumor, radiation therapy, or suppression of tumor growth using somatostatin analogues.

Corticotrolinoma

Tumors that secrete ACTH are rare, usually their size does not exceed 1 cm. Ovulation disturbance occurs due to an increase in the level of adrenal hormones; the level of free cortisol in urine can increase to 150 mcg/day or more. Transsphenoidal adenomectomy is usually performed, which is effective in 60-90% of cases. Drug treatment is aimed at suppressing ACTH production or blocking the interaction of cortisol with receptors. In clinical practice, the somatostatin analogue pasireotide and the glucocorticoid receptor antagonist mifepristone are used. New directions of treatment using the steroidogenesis inhibitor LC1699 and retinoic acid are being considered (clinical research stage).

Gefitinib, an epidermal growth factor receptor antagonist, is being studied in vitro. Long-term observation is indicated for any treatment method.

Thyrotropinoma

Thyrotropinoma is a rare cause of thyrotoxicosis. The introduction into practice of a highly sensitive method for determining TSH using ELISA has made the diagnosis of this condition more accessible; It has become possible to detect a tumor early, which helps to avoid diagnostic errors and incorrect treatment. However, there are no diagnostic methods specific for this pathology, therefore, when diagnosing thyrotropinomas, an increase in the level of the α-subunit of TSH, an increase in the level of SHBG, a decrease or absence of the response of thyrotropic cells to the administration of thyrotropin-releasing hormone, and the results of a suppressive test with T3 are taken into account. In most cases, the tumor size is relatively small (average 3 mm), which makes diagnosis difficult using CT and MRI. Treatment is usually surgical; if ineffective, radiation therapy is prescribed after it. Drug therapy with somatostatin analogues reduces TSH secretion in more than 90% of cases.

Gonadotropinoma

Previously it was believed that pituitary adenomas secreting FSH and LH. are extremely rare. However, it has recently been shown that hormonally inactive tumors in women can produce gonadotropic hormones. Administration of thyroliberin leads to an increase in the levels of FSH, LH, and the α- and β-subunits of LH in some, but not all, cases. Cases of hypergonadotropic amenorrhea with extremely high levels of gonadotropins have been described, in which stimulation of ovarian function with menotropin restores ovulation and leads to pregnancy.

(weakening of hormone formation): cerebral circulatory disorders (stroke); massive blood loss; tumor processes or metastases; skull injuries; surgical treatment of brain pathologies, radiation therapy; severe course of viral diseases, infections; encephalitis, meningitis; late toxicosis of pregnancy; autoimmune inflammation; congenital hypoplasia of the pituitary gland.

The main reason for the increased formation of hormones- this is an adenoma.

Disorders of the pituitary gland can lead to tumor, vascular diseases of the brain, trauma, surgery, blood loss, congenital anomalies. They manifest themselves in the form of insufficient or excessive production of hormones. In patients, growth, functioning of the reproductive and thyroid glands, kidneys, adrenal glands, milk secretion, and labor in women change. Men suffer from impotence and loss of libido.

The pituitary gland has two parts– anterior (adenohypophysis) and posterior (neurohypophysis). The first produces: prolactin, somatotropin, thyrotropin, adrenocorticotropic, gonadotropic hormones. Vasopressin accumulates in the posterior part, and melanocyte-stimulating factor is synthesized in the intermediate cells, which is responsible for skin color and adaptation of the eyes to darkness. These properties of pituitary tropic hormones are among the main ones. A deficiency or excess of any of them causes a chain of pathological reactions in the body. Often diagnosed with infertility, emaciation or obesity.

differs in a variety of characteristics. All pathological conditions, depending on the change in function, are divided into: with a decrease in the formation of hormones :

(Simmonds and Sheehan syndrome), pituitary dwarfism, diabetes insipidus;
with increased hormonal synthesis:, gigantism, Itsenko-Cushing's disease, hyperprolactinemia.

Diagnosis of the condition includes: blood and urine tests for hormones, x-rays of the skull bones, MRI and CT, PET of the brain, angiography to detect vascular disorders, tests with liberins of the hypothalamus, as they control the functioning of the pituitary gland.

PET CT scan of the brain with methionine

To assess the functioning of target organs, it is necessary to determine sex and thyroid hormones in the blood.

For hormonal deficiency replacement therapy with pituitary hormone analogues is used. If a tumor is detected, drug, radiation or surgical treatment may be chosen. They are often used in combination. One alternative method is to freeze part of the gland using a catheter that is passed through the sphenoid bone at the base of the skull.

Read more in our article about dysfunction of the pituitary gland, possible diseases, their symptoms and treatment.

Read in this article

Causes of pituitary gland dysfunction

The weakening of hormone formation can lead to:

cerebral circulatory disorders - ischemic or hemorrhagic stroke;
massive blood loss - at risk are women with frequent abortions, difficult childbirth, patients with ulcerative defects in the stomach, intestines, who have undergone trauma or extensive surgery;
tumor processes or metastases;
skull injuries;
surgical treatment of brain pathologies, radiation therapy;
severe course of viral diseases, malaria, tuberculosis or syphilitic infections;
encephalitis, meningitis;
late toxicosis of pregnancy;
autoimmune inflammation;
congenital hypoplasia of the pituitary gland.

The main reason for the increased formation of hormones is adenoma. Its cells are capable of hormonal production, while the remaining parts of the pituitary gland are compressed by the tumor, which leads to a significant decrease in other pituitary hormones.

It accumulates in the back, it retains water in the body and increases uterine contractions and milk secretion. The intermediate cells synthesize melanocyte-stimulating factor, which is responsible for skin color and eye adaptation to darkness. These properties of pituitary tropic hormones are among the main ones. In addition to these, they have many additional functions. A deficiency or excess of any of them causes a chain of pathological reactions in the body.

Prolactin

With a decrease in education, women have poorly developed mammary glands, and milk production decreases or stops after childbirth. A pathological increase in the formation of the hormone causes galactorrhea - the flow of milk outside of pregnancy and childbirth, combined with menstrual irregularities.

Somatotropin

Growth hormone deficiency leads to dwarfism (), growth retardation or gigantism, acromegaly with excess somatotropin.

Thyrotropin

With increasing concentration, it stimulates the formation and release of thyroxine and triiodothyronine into the blood by the thyroid gland, leading to hyperthyroidism. Low levels of thyroid-stimulating hormone cause hypothyroidism. This condition is more common and occurs when adenomas or destruction of cells of the anterior pituitary gland.

Adrenocorticotropic hormone

With its increased production, the release of the hormone of the adrenal cortex (cortisol), sex hormones (estrogens and progesterone) increases. Hypercortisolism syndrome occurs (). Low amounts of adrenocorticotropic hormone (ACTH) lead to adrenal insufficiency.

Since ACTH and cortisol are in feedback, then with primary damage to the adrenal glands (Cushing's syndrome, cancer), ACTH is below normal.

Gonadotropic

Impaired formation of follicle-stimulating and luteinizing hormone in women leads to uterine bleeding and menstrual irregularities, and in men they provoke impotence and infertility, enlarged mammary glands (gynecomastia)

Vasopressin

With its deficiency, diabetes insipidus develops - urine is produced abundantly, excess vasopressin leads to fluid retention in the body and an increase in edema.

Oxytocin

A decrease in hormone synthesis slows down labor, inhibits contractions, and leads to postpartum hemorrhage due to insufficient contraction of the uterus, it disrupts the activity of the mammary gland when feeding the child.

Symptoms of pituitary gland dysfunction in women and men

The clinical symptoms of pituitary diseases are characterized by a variety of signs. This is due to the proximity of cells responsible for different vital parameters and important role tropic hormones in the regulation of the endocrine system.

All pathological conditions, depending on changes in function, are divided into:

with decreased hormone production: hypopituitarism (Simmonds and Sheehan syndrome), pituitary dwarfism, diabetes insipidus;
with increased hormonal synthesis: acromegaly, gigantism, Itsenko-Cushing's disease, hyperprolactinemia.

Watch the video about hormonal levels and the pituitary gland:

Simmonds syndrome

The formation of all pituitary hormones is disrupted, which is accompanied by the development of the following symptom complex:

sudden weight loss with loss of subcutaneous fat, volume of muscle tissue and reduction in size internal organs;
decreased sweat secretion, dry and wrinkled skin of a gray-sallow color, blueness of the fingers;
teeth decay and hair falls out;
in children, growth slows down (dwarfism), the formation of sexual characteristics, and mental development;
in men – low potency and libido, hair loss on the chin, pubic area, armpits, the size of the prostate and external genital organs decreases;
in women, menstruation stops, the mammary glands and uterus atrophy, nipple pigmentation disappears;

due to low levels of thyroid hormones, lethargy, muscle weakness, drowsiness, constipation appear, the pulse slows down and blood pressure drops, body temperature decreases;
a decrease in ACTH is accompanied by hypotension, weak immunity, and a drop in blood sugar concentration;
from the nervous system - low motor and mental activity, apathy, depressive reactions, rapid aging, radiculitis with severe pain, polyneuritis, convulsions.

Sheehan syndrome

Occurs after childbirth or abortion with severe blood loss. In patients, milk production stops, menstruation decreases or completely disappears. There is swelling of the body, weakness, low activity, and drowsiness. The skin loses its elasticity, hair falls out, and nails become brittle. Patients report frequent dizziness and fainting.

Sheehan syndrome

Pituitary dwarfism

Violation of somatotropin formation leads to inhibition of growth and formation of internal organs. Accompanied by:

a lag in the development of the muscular and skeletal system, the maximum height of patients reaches 120-130 cm in adulthood;
underdevelopment of the genital organs, heart, lungs, kidneys, liver;
low blood pressure, bradycardia;
mental development is close to normal, the emotional sphere is close to youthful.

Diabetes insipidus

Patients have severe thirst and excessive urine production, which disrupts sleep. The volume of fluid loss can reach 5-20 liters per day. If the patient tries to drink less and reduce urination, this leads to severe dehydration.

Acromegaly

Appears in adults in the form of enlargement of the nose, ears, lower jaw, lips, disproportionately big hands and legs. Because of high level growth hormone, patients report pain in bones and joints, headaches, impaired vision, functioning of the heart, lungs, and genital organs. Patients are often diagnosed with malignant and benign tumors.

Gigantism

Hyperprolactinemia

With an increase in the formation of prolactin in women, the menstrual cycle is disrupted, such as scanty periods (oligomenorrhea) or their absence (amenorrhea). Following this, milk-like drops begin to be released from the mammary glands of nulliparous women, and hair growth on the body and chin increases. Nipple discharge also occurs in men. They are characterized by impotence and low libido, enlarged mammary glands. Excess prolactin leads to infertility in both sexes.

Watch the video about hyperprolactinemia:

Diagnosis of the condition

To examine patients, the following is prescribed:

blood and urine test for hormones;

To assess the functioning of target organs, it is necessary to determine sex, thyroid hormones, and cortisol in the blood.

Treatment of pathologies

For hormonal deficiency, replacement therapy with pituitary hormone analogues is used. If a tumor is detected, drug, radiation or surgical treatment may be chosen. They are often used in combination.

One alternative method is to freeze part of the gland using a catheter that is passed through the sphenoid bone at the base of the skull.

Disturbances in the functioning of the pituitary gland can be caused by a tumor, vascular diseases of the brain, trauma, surgery, blood loss, and congenital developmental anomalies. They manifest themselves in the form of insufficient or excessive production of hormones.

In patients, growth, the functioning of the reproductive and thyroid glands change. Read more about diffuse toxic goiter.

Often diagnosed with infertility, emaciation or obesity. To study the function of the pituitary gland, it is necessary to conduct blood and urine tests for hormone levels, as well as MRI, CT, and PET scan of the brain to exclude a tumor. Treatment of diseases is medicinal; for neoplasms, it is combined with surgery and radiation therapy.

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