The pituitary gland consists of two parts front anterior pituitary, where the products of their own six pituitary hormones (growth hormone, thyrotropin, follitropin, lyutropin, prolactin, and adrenocorticotropic hormone), and the back, where they can accumulate two hormones synthesized by the hypothalamus, oxytocin and vasopressin.
Pituitary adenoma is a benign tumor of glandular tissue, which is located in the anterior pituitary.
The causes of pituitary adenomas so far not completely understood. Contributing factors are:
infectious processes in the nervous system
injury of skull and brain
various adverse effects on the fetus during pregnancy.
Recently, given the value and duration of oral contraceptive drugs.
Pituitary adenomas are hormonally inactive (insidentaloma), if the cells from which they are composed do not produce hormones and hormonally active.
To hormonally active pituitary adenoma include:
growth hormone produced by adenoma:
produced growth hormone - somatropin;
prolactin secreting adenoma:
adenoma in the hormone prolactin is synthesized;
a pituitary adenoma secreting adrenocorticotropic hormone, stimulates the adrenal cortex;
tirotropny produced hormone that stimulates the thyroid gland;
folltropin produced or lyutropinprodutsiruyuschaya (gonadotropin). This is a pituitary adenoma producing gonadotrophic hormones that stimulate the work of the gonads.
The size of pituitary adenomas classified as:
microadenoma (from 1 mm to 2 cm in diameter)
makroadenomy - more than 2 cm in diameter.
Manifestations of pituitary adenomas depend on whether the hormone producing cells in the adenomas, the size of the adenoma and its rate of growth.
Adenoma producing somatotropin, manifest appearance of acromegaly, or if they occur in childhood gigantism.
Synthesizing prolactin adenoma - is the most common of pituitary adenomas. It grows slowly and usually manifests an increase in mammary glands and the release of milk from the mammary glands. Sometimes such an adenoma may produce defective hormone and not clinically manifest.
Kortikotropinoma that synthesizes adrenocorticotropic hormone, appears enhanced production of adrenal hormones, and Cushing. Usually, this adenoma synthesises many kortikotropnogo hormone, but grows slowly.
Tirotropinoma usually occurs in patients with gipotirozom (deficiency of thyroid function). It can cause thyrotoxicosis, which is extremely resistant to treatment, both medical and surgical.
Adenomas that produce hormones regulate gonadal function (gonadotropinoma) in men cause of impotence and gynecomastia in women - the menstrual cycle, uterine bleeding.
Are extremely rare malignant pituitary adenoma. With the growth of adenomas arise manifestation of the central nervous system. Next to the pituitary gland is crossing the optic nerve (chiasm), so if an adenoma is increased to two centimeters, having blurred vision. In the study of useful vision, identify their narrowing. In the fundus, with an increase in the size of adenomas, are the nipples swelling of the optic nerve. In the end, can occur optic atrophy, which results in a sharp drop in vision, blindness. With a significant increase in adenoma join violations of the cranial nerves.
Treatment of pituitary adenomas.
Medical treatment of pituitary adenomas performed by use of the drug Parlodel (bromocriptine). The most effective was he in the treatment of prolactin.
Of radiation treatment are used:
Radiosurgical method involves the introduction of radioactive substances in the adenoma. Ray treatments yield good results for small adenomas.
Neurosurgical treatment is carried out in the event of impairment, at the complicated adenomas (hemorrhage in the adenoma, cyst formation in adenoma).
Now operated on using microsurgical transsphenoidal approach. Surgical treatment usually gives good results, especially if the size of a small adenoma.