The pituitary gland is located
in the recess of the sphenoid bone of the skull called the sella turcica
. The pituitary gland is the main central endocrine gland, which produces a number of hormones that regulate the function of peripheral endocrine glands
. Besides the pituitary stimulates the growth of the body and the formation of breast milk
. The pituitary gland secrete two parts - the front (anterior pituitary) and rear (neurohypophysis)
. Cells adenogipofiza produce thyroid stimulating hormone (stimulates the thyroid gland), adrenocorticotropic hormone (stimulates the adrenal glands), gonadotropic hormones (affect the sex glands in men and women), and prolactin (stimulates lactation) and growth hormone (stimulates)
. Neurohypophysis accumulates in the blood and secretes vasopressin (reduces the volume of urine) and oxytocin (increases muscle tone of the uterine fibers)
. Pituitary disease can manifest reduction or increase of its hormonal activity, also may cause tumors
. Pituitary tumors may produce hormones or to be inactive in this respect
Neoplasms of the hypothalamic-pituitary region
The primary neoplasm in sella are macro- and microadenomas of the pituitary gland, craniopharyngiomas, meningiomas
. Pituitary adenomas account for approximately 15% of all intracranial tumors
. The difficulties of diagnosis are possible because of the small size of tumors of the pituitary gland
. Hormonally inactive pituitary education often manifest themselves later, when the symptoms of compression of the surrounding tissues
. Adenomas are classified by hormonal activity and size
. In secretory activity dominated prolactinoma, and somatotropinomy kortikotropinomy
. Sometimes hormonal activity is mixed
. A quarter of all adenomas does not produce hormones
. Based on the size and invasive properties of pituitary tumors are divided into two stages: microadenomas, macroadenoma
. Microadenomas less than 10 mm in diameter, do not alter the structure of the sella and do not cause symptoms of compression of the surrounding tissues
. Larger tumors are called macroadenomas
Symptoms of pituitary microadenomas
Microadenomas of the pituitary gland is often a random finding. This is associated with a high prevalence currently imaging diagnostic techniques, including computed and magnetic resonance imaging of the brain. Often this study appoint a neurologist. But sometimes the patient decides to go alone imaging of the brain, for whatever reasons. X-rays of the skull is not informative with respect to the pituitary microadenomas.
Symptoms of pituitary microadenomas depend only on its hormonal activity. Microadenomas not compresses surrounding tissue, so the visual field disturbances and headache usually does not happen. As mentioned previously, 25% of pituitary tumors have hormonal activity. Microadenomas more often are not secreted. In this case, the tumor does not cause any complaints and is not a reason for seeking medical help.
Gormonalnoaktivnye microadenomas often are prolactinomas. These tumors are common among women. Prolactin inhibits ovulation stimulates lactation, promotes weight gain. Usually women go to the doctor with complaints of menstrual disorders and infertility. Less often at very high levels of prolactin may be discharge from the breast (spontaneous or on pressure). If prolactinoma occurs in men, impotence and the possible discharge from the breast. Excess prolactin manifested by increased body weight in the normal mode of the day, the diet.
produce growth hormone. Such microadenomas appear in adults and children differently. Children somatotropinomy manifested primarily excessive increase in body length. In adults, bone growth zones are closed, so it is impossible to increase the length of the body. The excess growth hormone causes acromegaly. Clinically, the disease is manifested by an increase of the hands and feet, the thickness of the fingers, brow growth, coarsening of facial features. The voice becomes lower. Acromegaly is a secondary diabetes mellitus, hypertension, increases the risk of cancer pathology.
Kortikotropinomy produce adrenocorticotropic hormone. This hormone stimulates the production of cortisol in the adrenal glands. Patients developing Cushing's disease. The first appearance of the patient changes. The limbs become thinner due to muscle atrophy and fat redistribution, excessive subcutaneous fat is deposited primarily in the abdominal area. On the skin of the anterior abdominal wall appears bright stretch more than 1 cm in thickness (striae). The face becomes lunoobraznym, always present on the cheeks blush. In patients develop secondary diabetes and hypertension. Often there are changes in mental reactions and behavior.
Causes of pituitary microadenomas
The cause of pituitary microadenomas may be several factors. The basis of tumor formation in this area is a genetic predisposition, female gender, have the same meanings as pituitary function overload. These overloads may include pregnancy, childbirth, abortion, breastfeeding, hormonal contraception. In addition to these factors, the cause of pituitary microadenomas can become infectious process in the central nervous system, head injuries.
Treatment of pituitary microadenomas
Treatment of pituitary microadenomas depends on the hormonal activity. If education does not release hormones, the only tactics against him should be monitored.
Prolaktinomy successfully treated conservatively. The endocrinologist appoints cabergoline or bromkreptin long term under the control of monthly hormonal studies and regular MRI. Most prolactinomas are reduced in size and for 2 years lose hormonal activity. In the absence of effect of conservative treatment, the patient is sent to the operation. Radiation therapy is rarely used.
Surgical treatment is essential for growth hormone and corticotropin. Sometimes radiation therapy data neoplasms. There are drugs to suppress the activity of the pituitary microadenomas. Somatotropinomy decrease in size and lose activity when using synthetic somatostatin analogue (Octreotide and lanreotide). Kortikotropinomy respond to treatment hloditanom (an inhibitor of the biosynthesis of hormones in the adrenal cortex) combined with the appointment of reserpine, Parlodel, difenina, Peritol. The most common medications used to prepare for radical treatment and aftercare period. In case of failure of surgical treatment and radiotherapy is applied only conservative treatment.