Hypophysis tumors – group good-quality, are more rare – malignant new growths of a forward share (adenogipofiz) or a back share (neurohypophysis) of gland. Hypophysis tumors, statistically, make about 15% of new growths of intra cranial localization. They are equally often diagnosed for persons of both floors, usually at the age of 30-40 years. The vast majority of tumors of a hypophysis make adenomas which are subdivided into several types depending on the sizes and hormonal activity. Symptoms of a tumor of a hypophysis represent a combination of signs of volume intracerebral process and hormonal violations. Diagnosis of a tumor of a hypophysis is performed by carrying out a number of clinical and hormonal trials, an angiography and MRT of a brain.
Hypophysis tumors – group good-quality, are more rare – malignant new growths of a forward share (adenogipofiz) or a back share (neurohypophysis) of gland. Hypophysis tumors, statistically, make about 15% of new growths of intra cranial localization. They are equally often diagnosed for persons of both floors, usually at the age of 30-40 years.
The hypophysis is the endocrine gland which is carrying out the regulatory coordinating function concerning some other endocrine glands. The hypophysis is located in a pole of the Turkish saddle of a wedge-shaped bone of a skull, anatomic and functionally tied with department of a brain – a hypothalamus. Together with a hypothalamus the hypophysis makes the uniform neuroendocrine system providing constancy of a homeostasis of an organism.
In a hypophysis allocate two shares: forward – and back – a neurohypophysis. The hormones of a forward share produced adenogipofizy are: Prolactinum stimulating milk secretion; the somatotropny hormone influencing growth of an organism through regulation of proteinaceous exchange; the tireotropny hormone stimulating metabolic processes in a thyroid gland; AKTG regulating function of adrenal glands; the gonadotropny hormones influencing development and function of gonads. In a neurohypophysis are formed oxytocin stimulating sokratitelny ability of a uterus, and the antidiuretichesky hormone regulating process of a reabsorption of water in tubules of kidneys.
Abnormal growth of cells of gland leads to formation of tumors of forward or back department of a hypophysis and violation of hormonal balance. Sometimes to the area of a hypophysis sprout meningioma – tumors of brain covers; less often gland is surprised metastatic eliminations of malignant new growths of other localizations.
Reasons of tumors of a hypophysis
The reliable reasons of development of tumors of a hypophysis are up to the end not studied though it is known that some types of new growths can be caused genetically.
The number of the factors contributing to development of tumors of a hypophysis includes neuroinfections, chronic sinusitis, craniocereberal injuries, hormonal changes (including owing to prolonged use of hormonal medicines), an adverse effect on a fruit during pregnancy.
Classification of tumors of a hypophysis
Tumors of a hypophysis are classified taking into account their amount, an anatomic arrangement, endocrine functions, features of microscopic coloring etc. Depending on the size of a new growth allocate microadenomas (less than 10 mm in the maximum diameter) and macroadenomas (with the largest diameter more than 10 mm) a hypophysis.
On localization in iron distinguish tumors of an adenogipofiz and a neurohypophysis. Hypophysis tumors on topography of rather Turkish saddle and the structures surrounding it happen endosellyarny (overstepping the bounds of the Turkish saddle) and intrasellyarny (located within the Turkish saddle). Taking into account histologic structure of a tumor of a hypophysis are subdivided into malignant and good-quality new growths (adenomas). Adenomas proceed from ferruterous fabric of a forward share of a hypophysis (adenogipofiz).
Also the hormonal and active adenomas (producing this or that hormone) which meet in 75% of cases are divided by functional activity of a tumor of a hypophysis on hormonal and inactive ("mute", insidentaloma). Distinguish from hormonal and active tumors of a hypophysis:
- somatotropny adenoma
- somatotropinoma – the hypophysis tumor synthesizing - growth hormone;
- prolaktinovy adenoma
- prolaktinoma – the hypophysis tumor synthesizing hormone Prolactinum;
- kortikotropny adenoma
- kortikotropinoma - a hypophysis tumor, sekretiruyushchy AKTG, stimulating function of bark of adrenal glands;
- tirotropny adenoma
- tirotropinoma - a hypophysis tumor, sekretiruyushchy the tirotropny hormone stimulating function of a thyroid gland;
Folltropinprodutsiruyushchy or lyutropinprodutsiruyushchy adenomas (gonadotropny). These tumors of a hypophysis sekretirut the gonadotrophins stimulating function of gonads.
Hormonal and inactive tumors of a hypophysis and prolaktinoma meet most often (in 35% of cases respectively), somatotropinprodutsiruyushchy and AKTG-produtsiruyushchiye adenomas – in 10-15% of cases of all tumors of a hypophysis, other types of tumors are formed seldom. On features of microscopy distinguish hromofobny tumors of a hypophysis (hormonal and inactive adenomas), atsidofiliny (prolaktinoma, tirotropinoma, somatotropinoma) and bazofilny (gonadotropinoma, kortikotropinoma).
Development of the hormonal and active tumors of a hypophysis producing one or several hormones can lead to development of the central hypothyroidism, Cushing's syndrome, akromegaliya or giantism etc. Damage gormonoprodutsiruyushchy with a growth of adenoma can cause a condition of a gipopituarizm (hypophysial insufficiency). At 20% of patients the asymptomatic course of tumors of a hypophysis which are found only at autopsy is noted. Clinical displays of tumors of a hypophysis depend on hyper secretion of this or that hormone, the sizes and growth rate of adenoma.
Symptoms of tumors of a hypophysis
In process of increase in a tumor of a hypophysis symptoms from endocrine and nervous systems develop. Somatotropinprodutsiruyushchy adenomas of a hypophysis lead to emergence of an akromegaliya at adult patients or giantism if they develop at children. Prolaktinsekretiruyushchy adenomas are characterized by slow growth, shown amenorey, ginekomastiy and galaktorey. If such tumors of a hypophysis produce defective Prolactinum, then clinical manifestations can be absent.
AKTG-produtsiruyushchiye adenomas stimulate secretion of hormones of bark of adrenal glands and lead to development of a giperkortitsizm (Cushing's disease). Usually such adenomas grow slowly. Tirotropinprodutsiruyushchy adenomas quite often accompany a current of a hypothyroidism (functional insufficiency of a thyroid gland). They can cause the persistent thyrotoxicosis extremely steady against drug and surgical treatment. The Gonadotropny adenomas synthesizing sex hormones at men lead to development of a ginekomastiya and impotence, at women – to violation of a menstrual cycle and uterine bleedings.
Increase in the sizes of a tumor of a hypophysis leads to development of manifestations from nervous system. As the hypophysis anatomic adjoins to an optic chiasm (hiazmy), at increase in the sizes of adenoma up to 2 cm in the diameter visual violations develop: the narrowing of fields of vision, hypostasis of nipples of an optic nerve and its atrophy leading to sight falling up to a blindness.
Adenomas of a hypophysis of the big sizes cause the sdavleniye of cranial nerves which is followed by symptoms of defeat of nervous system: headaches; doubling in eyes, , , restriction of movements of eyeballs; spasms; persistent cold; dementia and changes of the personality; increase in intra cranial pressure; hemorrhages in a hypophysis with development of sharp cardiovascular insufficiency. At an involvement into process of a hypothalamus consciousness violation episodes can be observed. Malignant tumors of a hypophysis meet extremely seldom.
Diagnosis of tumors of a hypophysis
Necessary researches at suspicion of a tumor of a hypophysis are careful ophthalmologic and hormonal inspections, neurovisualization of adenoma. The research of urine and blood on the content of hormones allows to establish a type of a tumor of a hypophysis and degree of its activity. Ophthalmologic inspection includes assessment of sharpness and the fields of vision allowing to judge an involvement into process of optic nerves.
The X-ray analysis of a skull and zone of the Turkish saddle, brain MPT and KT allows to carry out neurovisualization of a tumor of a hypophysis. Radiological increase in the sizes of the Turkish saddle and an erosion of its bottom, and also increase in the lower jaw and bosoms of a nose, a thickening of bones of a skull, and expansion of interdental intervals can be defined. By means of MRT of a brain it is possible to see tumors of a hypophysis with a diameter less than 5 mm. The computer tomography confirms existence of adenoma and its exact sizes.
At macroadenomas the angiography of vessels of a brain indicates the shift of a carotid and allows to differentiate a hypophysis tumor with intra cranial aneurism. In the analysis of cerebrospinal fluid the increased level of proteins can be defined.
Treatment of tumors of a hypophysis
Today in treatment of tumors of a hypophysis the endocrinology applies surgical, beam and medicinal methods. For each type of tumors of a hypophysis there is a specific, most optimal variant of treatment which is selected the endocrinologist and the neurosurgeon. Surgical removal of a tumor of a hypophysis is considered the most effective. Depending on the sizes and localization of adenoma its frontal removal via the optical device, or the resection through a wedge-shaped bone of a skull is carried out or. Expeditious removal of tumors of a hypophysis is supplemented with radiation therapy.
Hormonal and inactive microadenomas are treated by means of radiation therapy. Performing radiation therapy is shown in the presence of contraindications to expeditious treatment, and also elderly patients. In the postoperative period gormonozamestitelny therapy (a cortisone, tireoidny or sex hormones), if necessary - correction of electrolytic exchange and insulin therapy is carried out.
From medicines use the dopamine agonists (, ) causing wrinkling Prolactinum - and AKTG-sekretiruyushchy tumors of a hypophysis, and also , the lowering level of corticosteroids at patients with Cushing's syndrome. An alternative method of treatment of tumors of a hypophysis is freezing of the site of fabric of gland by means of the probe entered through a wedge-shaped bone.
The forecast at hypophysis tumors
The further forecast at hypophysis tumors in many respects is defined by the sizes of adenomas, a possibility of their radical removal and hormonal activity. At patients from prolaktinoma and somatotropinomam the complete recovery of hormonal function is observed in a quarter of cases, at adrenokortikotropinprodutsiruyushchy adenomas - in 70-80% of cases.
Macroadenomas of a hypophysis more than 2 cm in size completely cannot be removed therefore their recurrence during 5-year term after operation is possible.