Microadenoma of the pituitary gland
The pituitary gland is located in a depression in the sphenoid bone of the skull called the Turkish saddle. The pituitary gland is the main central endocrine gland that produces a number of hormones that regulate the function of the peripheral endocrine glands. In addition, the pituitary gland stimulates the growth of the body and the formation of breast milk. In the pituitary gland, two lobes are distinguished - the anterior (adenohypophysis) and the posterior (neurohypophysis). The cells of the adenohypophysis produce thyroid stimulating hormone (stimulates the thyroid gland), adrenocorticotropic hormone (stimulates the adrenal glands), gonadotropic hormones (affects the sex glands in men and women), as well as prolactin (stimulates lactation) and growth hormone (stimulates growth). The neurohypophysis accumulates and secretes vasopressin into the blood (decreases the volume of urine) and oxytocin (increases the tone of the muscle fibers of the uterus). Diseases of the pituitary gland can be manifested by a decrease or increase in its hormonal activity, and the appearance of neoplasms is also possible. Pituitary tumors can produce hormones or be inactive for that matter.
Hypothalamic-pituitary neoplasms
The main neoplasms in the area of the sella turcica are macro- and microadenomas of the pituitary gland, craniopharyngiomas, meningiomas. Pituitary adenomas account for approximately 15% of all intracranial neoplasms. Difficulties in diagnosis are possible due to the small size of the pituitary neoplasms. Hormonally inactive formations of the pituitary gland often manifest themselves late, when symptoms of compression of the surrounding tissues appear. Adenomas are classified by hormonal activity and size. By secretory activity, prolactinomas, somatotropinomas and corticotropinomas predominate. Sometimes hormonal activity is mixed. A quarter of all adenomas do not produce hormones. Based on their size and invasive properties, pituitary tumors are divided into 2 stages: microadenomas, macroadenomas. Microadenomas less than 10 mm in diameter,do not change the structure of the sella turcica and do not cause symptoms of compression of the surrounding tissues. Larger tumors are called macroadenomas.
Symptoms of the pituitary microadenoma
The pituitary microadenoma is often an accidental finding. This is due to the high prevalence of imaging diagnostic techniques, including computed tomography and magnetic resonance imaging of the brain. Often such a study is prescribed by a neurologist. And sometimes the patient independently decides to undergo a brain tomography for some reason. X-ray of the skull is not informative in relation to pituitary microadenomas.
Symptoms of the pituitary microadenoma depend only on its hormonal activity. Microadenoma does not squeeze the surrounding tissues, so visual field disturbances and headaches usually do not occur. As mentioned earlier, 25% of all pituitary neoplasms have no hormonal activity. Microadenomas are even more often non-secreting. In this case, the neoplasm does not cause any complaints and is not a reason for seeking medical help.
Hormonally active microadenomas are most often prolactinomas. These tumors are common among women. Prolactin suppresses ovulation, stimulates lactation, and promotes weight gain. Usually women go to the doctor with complaints of menstrual irregularities and infertility. Less often, with a very high level of prolactin, discharge from the mammary glands (spontaneous or with pressure) is possible. If prolactinoma occurs in a man, then impotence and discharge from the mammary glands are possible. An excess of prolactin in the blood is manifested by an increase in body weight during the usual daily routine, nutrition.
Growth hormones produce growth hormone. Such microadenomas manifest themselves differently in adults and children. In children, somatotropinomas are manifested primarily by an excessive increase in body length. In adults, the growth zones of the bones are closed, so an increase in body length is impossible. Excess growth hormone causes acromegaly. Clinically, the disease is manifested by an increase in the hands and feet, the thickness of the fingers, the growth of the brow ridges, and the coarsening of facial features. The voice gets lower. Acromegaly causes secondary diabetes mellitus, arterial hypertension, and increases the risk of oncopathology.
Corticotropinomas produce adrenocorticotropic hormone. This hormone stimulates the production of cortisol in the adrenal glands. Patients develop Itsenko-Cushing's disease. First of all, the patient's appearance changes. The limbs become thinner due to muscle atrophy and the redistribution of adipose tissue, excess subcutaneous fat is deposited mainly in the abdomen. Bright stretch marks more than 1 cm in thickness (striae) appear on the skin of the anterior abdominal wall. The face becomes moon-shaped, there is always a blush on the cheeks. Patients develop secondary diabetes mellitus and arterial hypertension. Changes in mental reactions and behavior are common.
Causes of pituitary microadenoma
Several factors can be the cause of pituitary microadenoma. The formation of tumors in this area is based on a genetic predisposition, female sex, and functional overloads of the pituitary gland are also important. Such overloads include pregnancy, childbirth, abortion, breastfeeding, hormonal contraception. In addition to these factors, the cause of pituitary microadenoma can be an infectious process in the central nervous system, traumatic brain injury.
Treatment of pituitary microadenoma
Treatment of pituitary microadenoma depends on its hormonal activity. If education does not release hormones, then observation should be the only tactic in relation to it.
Prolactinomas are successfully treated conservatively. The endocrinologist prescribes cabergoline or bromocreptin for a long time under the supervision of monthly hormonal studies and regular magnetic resonance imaging. Prolactinomas often decrease in size and lose hormonal activity within 2 years. In the absence of the effect of conservative therapy, the patient is sent for surgery. Radiation therapy is rarely used.
Surgical treatment is essential for corticotropin and growth hormone. Radiation therapy for these neoplasms is sometimes performed. There are drugs to suppress the activity of these pituitary microadenomas. Somatotropinomas decrease in size and lose activity when artificial analogs of somatostatin (Lanreotide and Octreotide) are used. Corticotropinomas respond to the course of treatment with chloditan (an inhibitor of the biosynthesis of hormones in the adrenal cortex) in combination with the appointment of reserpine, parlodel, diphenin, peritol. Most often, drugs are used to prepare for radical treatment and in the postoperative period. In case of impossibility of surgical treatment and radiation therapy, only conservative treatment is used.
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The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
