HYPOPHYSIS (hypophysis, glandula pituitaria; synonym: brain appendage, pituitary gland) — the endocrine gland tied with hypothalamic area of a brain in uniform gipotalamogipofizarny system produces a number of the peptide hormones regulating function of closed glands.
the First references of G. meet in K. Galen and A. Vezaliya's works. Authors believed that through G. there is a release of the slime which is formed in a brain. T. Villizy considered that in G. cerebrospinal liquid is formed, and F. Marangdi believed that he, absorbs this liquid and allocates it in blood. The first morfol, the description of a structure of G. was made in 1867 by P. I. Peremezhko. It showed that in G. are available a bast layer (a front share), a cavity of a brain appendage and a white mozgovidny layer (a back share). Later A. Dostoyevsky (1884, 1886) and the Flash (Flesch, 1884), having carried out microscopic studying of G., found chromophobic and chromophilic cells in a front share. For the first time P. of Mari (1886) paid attention to communication of an acromegalia with a tumor of a hypophysis. He established G.'s role in regulation of growth of a body. However only in 1921 Evans (H. The m of Evans) proved that in G. the growth hormone is formed. Frelikh (1901) and Simmonds (M. of Simmonds, 1914) showed to A. Frohlich value G. in regulation of exchange processes. Pilot studies of B. Tsondek (1926, 1931) and Smith (R. E. of Smith, 1926) showed G.'s role in regulation of function of gonads. Afterwards from a front share of G. gonadotropic hormones, and also the hormones controlling function of a thyroid gland — thyritropic and adrenal glands — adrenocorticotropic [L. Loeb, were emitted 1929; Li (Page H. Li), 1942; G. Sayers and sotr., 1943]. In average, intermediate, G.'s share Melonotropinum (melanotsitostimuliruyushchy hormone) and lipotropin were found. Oliver and Schaefer (G. Oliver, E. A. Schafer, 1894) established that extracts of a back share of G. render angiotonic effect. Later hormones vasopressin and oxytocin were discovered.
In the 40th 20 century studying of morphology of a front share of G. in connection with function of peripheral glands begins, and also attempts biol are made, testings of hormonal activity of G., the preparative biochemistry of hypophyseal hormones develops. Studying correlative bonds between closed glands, M. M. Zavadovsky (1941) formulated the principle plus or minus of interaction (the law of regulation as a negative feed-back) that allowed to explain the mechanism of regulation of G. of function of others hemadens (see). In the subsequent researches of regulatory mechanisms of activity of closed glands the leading role of c was revealed. the N of page, in particular a hypothalamus, in control of tropny functions G.
G. develops from 2 germinal rudiments: ectoderms of an oral bay by protrusion of a pharyngeal (pituitary) pocket (Ratke's pocket) and neuroglial funneled protrusion of a brain at the level of a bottom of a cavity of the third ventricle. The pituitary pocket forms at the person on the 4th week of embryonic development and grows towards a diencephalon, from to-rogo protrusion in the form of a funnel (infundibulum) respectively is towards formed. Close contact of a funnel of a brain and pituitary pocket — the starting moment for a differentiation of separate parts of germinal. From neuroglial protrusion of a diencephalon the neurohypophysis forms further. The ventral wall of a pituitary pocket is a source for formation of a front share of G., and dorsal — for an intermediate (average) part. The cavity of a pocket is obliterated or can remain in the form of a pituitary crack between a front share and an intermediate part. To completion of process of an otshnurovka of a pituitary pocket from primary oral cavity there is overgrowing of the channel connecting them, from this point ferruterous part G. forms as a hemaden. In some cases at the adult the reduced embryonal pituitary course in the form of the vaskulyarizirovanny cellular tyazh going from a throat to a base of skull remains. Sometimes the remained rest of a pituitary pocket at the adult forms under a mucous membrane of a nasopharynx so-called pharyngeal.
At early stages of embryonic development (7 — the 8th week) there is a gradual differentiation of cells at first basphilic, and is later than an acidophilic row. In the subsequent (9 — the 20th week) there is a formation of processes of synthesis of hormones in a front share of G.
G. represents the reddish-gray formation of a fabiform form covered with the fibrous capsule. Its weight on average 0,5 — 0,6 g, the sizes 1x1, 3 X 0,6 see. Depending on a sex, age and in cases of diseases of endocrine system the sizes and G.'s weight change. Women have it slightly more in connection with cyclic changes of gonadotropic function. At advanced age the tendency to reduction of a front share is noted.
According to PNA and LNH, G. divide into two shares (fig. 1 and 2) having different development, a structure and function: front, distal, or adenohypophysis (lobus anterior, pars distalis, adenohypophysis), and back, or neurohypophysis. The adenohypophysis making apprx. 70% of gross weight of gland is conditionally divided into distal (pars distalis), voronkovy (pars infundibularis) and intermediate (pars intermedia) of a part, and a neurohypophysis — into the tail, or a share, and a pituitary leg.
It is located in a pituitary pole of the Turkish saddle of a wedge-shaped bone. The Turkish saddle from above is covered with a diaphragm — a spur of a firm meninx with an opening, through a cut there passes G.'s leg connecting it with a brain. Lateralno on both sides from G. cavernous sine are. Ahead and behind small venous branches form around G.'s funnel a ring — a circular sine (Ridley). This venous education separates G. from internal carotid arteries. An upper part of a front share of G. is covered with visual decussation and visual tracts.
Blood supply of. it is carried out by branches of an internal carotid artery (top and bottom pituitary arteries), and also branches of an arterial circle of a great brain (fig. 3). Upper pituitary arteries participate in blood supply of an adenohypophysis, and lower — a neurohypophysis, contacting to the neurosecretory terminations of axons of macrocellular kernels here hypothalamus (see). Upper pituitary arteries enter a median eminence of a hypothalamus where are scattered in a capillary network (primary capillary texture); then these capillaries (with to-rymi bombways of axons of small neurosecretory cells of a medio-basal hypothalamus contact) gather in the portal veins which are going down along a pituitary leg in a parenchyma of an adenohypophysis where again are divided into network of sinusoidny capillaries (a secondary capillary texture). Thus blood gets to an adenohypophysis, previously having passed through a median eminence of a hypothalamus where it is enriched with hypothalamic adenogipofizotropny hormones (rileasing-hormones).
Outflow of the blood saturated with adenogipofizarny hormones from numerous capillaries of a secondary texture is carried out on system of veins which in turn fall into venous sine of a firm meninx (cavernous and intercavernous) and further into the general blood stream. Thus, the portal system G. with the descending direction of a blood flow from a hypothalamus is a morfofunktsionalny component of the difficult mechanism neurohumoral control of tropny functions of an adenohypophysis (see. Gipotalamo-gipofizarnaya system ).
Innervation it is carried out by generally sympathetic fibers entering gland together with pituitary arteries. A source of a sympathetic innervation of an adenohypophysis are the postganglionic fibers going through the internal sleepy texture which is directly connected with upper cervical nodes. It is established that influence of sympathetic impulses on an adenohypophysis is not limited only to vasculomotor effect. At the same time the ultrastructure and secretory activity of ferruterous cells changes. The assumption of a direct innervation of a front share from a hypothalamus was not confirmed. Nerve fibrils of neurosecretory kernels of a hypothalamus come to a back share.
the Distal part of a front share of G. consists of numerous epithelial crossbeams (trabeculae epitheliales), spaces between to-rymi contain a large number of capillaries of sinusoidny type and elements of friable connecting and reticular fabric. In trabeculas distinguish two types of ferruterous cells-adenotsitov — chromophobic and chromophilic. Chromophobic adenotsita meet in 50 — 60% and are located in the center of gland. Cytoplasm of these cells is poorly painted and contains a small amount of organellas. Chromophobic adenotsita, apparently, can be sources of formation of other types of cells. The second look — chromophilic adenotsita, are located on the periphery of trabeculas and contain a large number of secretory granules in cytoplasm. Often adenotsita contact to capillaries. On ability to be painted selectively by acid or main dyes chromophilic cells are subdivided on acidophilic and basphilic. Acidophilic (or eosinophilic) cells have the oval form, in their cytoplasm there are a lot of large secretory granules which are painted an adhan in pink color. Unlike other cells of a front share, in cytoplasm of acidophilic cells a large number sulphhydryl and disulfide groups, and also phospholipids is revealed. In acidophilic cells the system of tubules of an endoplasmic reticulum is well-marked and many ribosomes contain that testifies to a high level of synthesis of protein in these cells. Acidophilic cells make 30 — 35% of total number of secretory cells of a front share, at the same time total quantity of basphilic cells does not exceed 10%. The sizes and a form of the last are very changeable and depend on a condition of a gormonoobrazovaniye in iron. Basphilic cells differ in larger sizes in comparison with acidophilic, have the rounded or polygonal shape. Cytoplasm of basphilic cells contains secretory granules in the form of grains of blue color (during the coloring by an adhan across Mallori). Unlike acidophilic cells, in basphilic cells the lamellar complex (Golgi) is well developed, secretory granules have considerably the smaller sizes.
Are the basis for functional classification of cells of a front share by gistokhy., ultrastructural and immunogistol. features of cells of G. and their reaction to changes of function of a certain hemaden.
In the functional relation acidophilic cells are divided into two subtypes (fig. 4, a): 1) the cells located in the center of gland and containing large (to 600 nanometers) secretory granules; these cells are functionally connected with secretion of lactogenic hormone (prolactin) and laktotropotsitam are called; 2) the cells located along vessels, which are painted oranzhy G, having secretory granules to 350 nanometers; are functionally connected with secretion of somatotropic hormone (growth hormone) and somatotropotsitam are called.
In turn basphilic cells are divided into three subtypes. Carry the cells of small size, rounded shape which are located around capillaries on the periphery of a share to the first subtype. In their cytoplasm there are a lot of glycoproteins, diameter of secretory granules apprx. 200 nanometers. These cells connect with formation of follicle-stimulating hormone and call follicle-stimulating gonadotropotsita.
Carry delta and basphilic adenotsita (delta cells) to the second subtype — cells of larger sizes which are located closer to the center of gland and do not contact to capillaries. Cells contain formations of rounded shape of dark and crimson color — a makula (apparently, a lamellar complex). In cytoplasm of these cells of glycoproteins it is much less, than in cells of the first subtype. Elektronnomikroskopicheski they differ from the previous subtype in lighter cytoplasmatic matrix and a form of a kernel. At the same time they have the similar sizes of granules. These cells responsible for formation of luteinizing hormone are called luteinizing gonadotropotsita. After castration the quantity of cells of the first and second subtypes increases, their hypertrophy is followed by accumulation in cytoplasm of glikoproteidny granularity and emergence among them the «cells of castration» containing large vacuoles. Administration of estrogen the castrated animal causes opposite changes in cells.
The third subtype — beta and basphilic adenotsita (beta cells) — the large cells of a polygonal form which are painted aldehyde-fuchsin, with the lowest maintenance of glycoproteins, glands which are located in the center far from vessels. In cytoplasm of beta cells the smallest secretory granules of 150 nanometers in size come to light. Functionally they are connected with formation of thyritropic hormone and tireotropotsitam are called (fig. 4, b). After removal or blockade of function of a thyroid gland in these cells ultrastructural changes (a cell of a thyroidectomy) are observed gistokhy, and.
Producers of adrenocorticotropic hormone are otrostchaty cells of a chromophobic row — the kortikotropotsita containing slabookrashivayushchuyusya cytoplasm capable to accumulate glycoproteins. They differ in Elektronnomikroskopicheski from other cells in a form, the low density of a matrix of cytoplasm. The sizes of their secretory granules make 200 nanometers. Granules have a peripheral zone of an enlightenment and more often come to light about cellular membranes. Secretory granules are synthesized in elements of a lamellar complex, allocated by an exocytosis in intercellular spaces in.
At the same time in a question about morfol, substrate of formation of hormones in an adenohypophysis there is other point of view, according to a cut all described kinds of basphilic and acidophilic cells reflect only their various functional state. In the course of a gormonoobrazovaniye in G. the close morfofunktsionalny interaction between separate types of secretory cells caused by rather balanced process of synthesis of hypophyseal hormones in various functional types of cells is noted.
The Voronkovy part of a front share is over a diaphragm of the Turkish saddle. Covering a leg of a hypophysis, it contacts to a gray hillock. The Voronkovy part consists of epithelial cells, krovosnabzhatsya plentifully. At gistokhy, a research in its cells hormonal activity is observed.
Intermediate (average) part G. is constructed of several layers of the large basphilic cells having secretory activity. Often here follicular cysts with colloid contents are observed. In cells of an intermediate share the melanotsitostimuliruyushchy hormone (interludes) connected with pigmental exchange is produced.
Back share of T. it is formed by a neuroglia of ependimny type and consists of cells of a spindle-shaped form — pituicytes, axons and bombways of gomoripolozhitelny neurosecretory cells of a front hypothalamus (see. Neurosecretion ). In a back share numerous hyaline glybk — the accumulative neurosecretory little bodies (Herringa) representing the expansions of axons and their bombway filled with large neurosecretory granules, mitochondrions and other inclusions are found. Neurosecretory granules are morfol. substrate of neurohormones — oxytocin and vasopressin. A variety of separate types of the ferruterous cells which are a part of a parenchyma of an adenohypophysis is explained first of all by the fact that the hormones produced by them are various by the chemical nature, and fine structure of the cells cosecreting them shall correspond to features of biosynthesis of each hormone. However sometimes it is possible to observe transitions of ferruterous cells from one version in another. So, in gonadotrofotsita aldehyde the ofuksinofilny granulation characteristic of tireotrofotsit can appear. Besides, the same ferruterous cells depending on localization can produce as adrenocorticotropic hormone, and melanotsitostimuliruyushchiya. Apparently, kinds of ferruterous cells of an adenohypophysis can be not genetically determined forms, and only different fiziol, conditions of basophiles or acidophiles.
G., being an endocrine organ, possesses various functions which are carried out by means of hormones of its lobby and a back share, and also an intermediate part. A number of hormones of a front share is called triple (e.g., thyritropic hormone). In a front share of G. hormones are produced: thyritropic hormone (see), adrenocorticotropic hormone (see), a growth hormone (see. Somatotropic hormone ), Prolaktin (see), follicle-stimulating hormone (see), luteinizing hormone (see), and also lipotropic factors of a hypophysis (see). In an intermediate part it is formed melanotsitostimuliruyushchy hormone (see), and in a back share collects vasopressin (see) and oxytocin (see).
Closely connected through a hypothalamus with all nervous system, G. combines in functional whole the endocrine system participating in ensuring constancy of internal environment of an organism. The concept «constancy» includes not only process of maintenance of the main constants of internal environment, but also the most adequate, optimum vegetative providing biol, functions of an organism, constant ensuring readiness for action. As the changing terms of the environment are dictated need various on biol, to value and motor manifestations of behavioural reactions, and parameters of internal environment shall change also adequately. Daily (circadian), monthly, seasonal and other biorhythmic fluctuations of parameters of internal environment, in particular concentration of hormones are known. It is possible to speak about homeostatic maintenance of constancy of hormones in blood and about gomeokinetichesky mechanisms of changes of their concentration (see. Homeostasis ). In endocrine system homeostatic regulation is carried out on the basis of the universal principle of a negative feed-back. The fact of existence of such communication between a front share of G. and «glands targets» (a thyroid gland, bark of adrenal glands, gonads) is fixed by numerous researches. Excess of glands target hormone brakes, and its shortcoming stimulates secretion and release of the corresponding throne hormone. The loop of a feed-back by all means joins a hypothalamus: in it there are sensitive to concentration receptor zones in blood of hormones of «glands targets». Catching deviations of concentration of hormones from necessary level, receptors of a hypothalamus activate or brake the relevant Hypothalamic centers managing work of a front share of G. by release of the corresponding hypothalamic adenogipofizarny hormones (see. Hypothalamic neurohormones ). Increasing or reducing products of tropny hormones, G. eliminates deviations of the glands target function. The main property of regulation on a deviation consists that the fact of a deviation of concentration of hormones of «glands targets» from norm is an incentive for return of these concentration to the set level. In turn «the set level» is not a constant for a long time. It changes, is sometimes considerable, at the expense of the gomeokinetichesky mechanisms transferring it to the new set level which further is so strictly supported by regulation «on a deviation». It is possible to explain with Gomeokinetichesky reorganization seasonal changes of concentration of hormones in blood, an ovarian and menstrual cycle, circadian fluctuations of quantity of oxyketosteroids etc.
Regulation «on indignation» is the cornerstone of a homeokinesis. The factor (ambient temperature, duration of light day, stressful situation, etc.) which does not have a direct bearing on concentration of hormone, revolting influences on ts.n.s, through sense bodys, including and those kernels of a hypothalamus which manage work of a front share of. In them there is also «a reorganization of level» which is adequately corresponding to future activity. In the course of homeostatic regulation «on a deviation» and in the course of gomeokinetichesky regulation «on indignation» the gipotalamogipofizarny complex acts as uniform, continuous whole.
As G. is the major link in system of somatovegetativny integration, disturbances of its function conduct to diskoordination of the vegetative and somatic sphere.
At disturbance of gormonoobrazovatelny function G. there are various syndromes. However sometimes strengthening of products or secretion of one of hormones does not lead to the expressed functional shifts. Excess products of somatotropic hormone (in particular, at acidophilic adenomas) bring to to giantism (see) or acromegalias (see). Insufficiency of this hormone is followed by pituitary dwarfism (see). Disturbances of products of follicle-stimulating and luteinizing hormones are the reason of sexual insufficiency or disorders of sexual functions. Sometimes after G.'s defeat disorder of regulation of sexual functions is combined with disturbances of a lipometabolism (cm, Adiposogenital dystrophy ). In other cases disorganization of hypothalamic regulation of an adenogipofizarny hormonopoiesis is shown by premature puberty (see).
During the strengthening of glikokortikoidny function of bark of adrenal glands in G. basphilic adenoma quite often is found out that connect with hyperproduction of adrenocorticotropic hormone (see. Itsenko — Cushing a disease ). Extensive destruction of a parenchyma of a front share of G. can bring to pituitary cachexia (see), at a cut owing to disturbance of gormonoobrazovatelny activity of a front share of G. functional activity of a thyroid gland and glikokortikoidny function of bark of adrenal glands decreases. It leads to disturbance of metabolism and to development of the progressing emaciation, an atrophy of bones, fading of sexual functions and an atrophy of generative organs.
Destruction of a back share of G. leads to development of not sugar mocheiznureniye (see. Diabetes not sugar ). This disease can arise as well at an intact back share of G. in cases of defeat of nadzritelny kernels of a front hypothalamus or a break of a pituitary leg.
Disturbance of blood circulation is shown by considerable vasodilatation and a hyperemia of gland. Sometimes at infectious diseases (a typhoid, sepsis, etc.), and also after craniocereberal injuries small Hemorrhages in fabric of gland are observed. Ischemic heart attacks of a front share of G. with the subsequent substitution of a nekrotizirovanny parenchyma connecting fabric most often arise after an embolism, is more rare after thrombosis of vessels. The sizes of heart attacks can be the most various, from micro to macroscopic. Sometimes the heart attack takes all front share of. For a wedge, manifestations of effect of full loss or the expressed dysfunction of G., according to B. P. Ugryumov (1963), existence of the extensive heart attack taking apprx. 3/4 volumes of a front share is necessary. Necroses in G. can be also a consequence of atherosclerotic defeat of vessels. Cases of hemorrhages with the subsequent development of a necrosis in an adenohypophysis at an eclampsia are described ‘.
The inflammation of a hypophysis and the fabrics surrounding it (perigipofizit) (hypophysitis) is observed at purulent processes in a wedge-shaped or temporal bone, and also at purulent meningitis. Inflammatory process, striking the capsule of gland, passes to a parenchyma, causing in it it is purulent - necrotic changes with destruction of ferruterous cells. Sometimes at septic embolisms in G. abscesses are formed.
Syphilis and tuberculosis affect G. seldom. At the disseminated form of tuberculosis in a parenchyma of gland miliary hillocks are observed, the large caseous centers, and in the capsule — infiltrates are more rare. At inborn syphilis in G. growth of interstitial connecting fabric with formation of gummas is found. Though G. at the acquired syphilis is surprised seldom, at syphilitic defeat of covers of a brain infiltration of the capsule of gland is observed by lymphocytes and plasmocytes. A wedge, manifestations of an inflammation of G. depend on extent of its damage. Defeat of all front share leads to a pituitary cachexia.
The hypoplasia and G.'s atrophy develops at senile age, its weight and the sizes decrease. At the same time reduction of number of acidophilic cells, disappearance in their cytoplasm of specific oxyphilic granularity and growth in a varying degree of connecting fabric is observed. At the same time a number of authors notes relative increase in quantity of basphilic cells, explaining thereby a possibility of emergence of hypertensia in people at advanced age. Cases of an inborn hypoplasia of G. about a wedge, are described by manifestations of pituitary insufficiency (see. Hypopituitarism ).
The hypoplasia and G.'s atrophy can appear at various damages of structures of a medico-basal hypothalamus, and also at disturbance of anatomic integrity of a leg of. In development of a secondary hypoplasia and G.'s atrophy long increase in intracranial pressure, and also a mechanical prelum of G. tumors of the basis of a brain can play a big role. Disturbance of protein and carbohydrate metabolism in secretory cells of G. brings in the subsequent to development of fatty dystrophy of a parenchyma. In literature isolated cases of an atrophy of ferruterous fabric as a result of the expressed sclerosis and a hyalinosis are described.
During pregnancy secretory function G. considerably is activated and develops its hyperplasia. Its weight at the same time increases on average from 0,6 — 0,7 g to 0,8 — 1 g. The functional hyperplasia of cellular elements of a front share is in parallel observed: the quantity of large cells with oxyphilic granularity («a cell of pregnancy») and at the same time number of chromophobic cells increases. Apparently, emergence of hypertrophied cells of an acidophilic row is result of transformation of the main cells of a front share. Similar on morfol, it are found to signs of a cell in R. at horionepitelioma. Permanent dysfunction or removal of other closed glands causes compensatory and adaptive reaction of. At the same time the hyperplasia of chromophobic, basphilic or acidophilic cells in an adenohypophysis also develops that in some cases leads even to developing of adenoma. So, at the patients who were exposed to local radiation of gonads in G. the number of chromophobic elements accrues and slightly the quantity of basphilic cells increases. A hypocorticoidism (see. Addisonova disease ) leads, as a rule, to a hypertrophy of chromophobic cells and to partial degranulation of basophiles. Replacement therapy by glycocorticoids normalizes a morfofunktsionalny condition of chromophilic cells y reduces number of the main cells in a front share. Long introduction of a cortisone or AKTG at intact adrenal glands leads to a hyperplasia of basphilic cells in which cytoplasm there is a special granularity revealed during the coloring according to Schiff on glycoproteins. These cells remind Kruk's cells. In case of an endogenous hypercorticoidism (see. Itsenko — Cushing a disease ) in G. the hyperplasia of basphilic elements with emergence in their cytoplasm of amorphous homogeneous substance is found. This phenomenon for the first time described by Kruk (A. S. Crooke) in 1946, was called «krukovsky hyalinization of basophiles». Similar changes in basphilic cells are observed also at the patients who died from other diseases. Diffusion, or focal, the hyperplasia of acidophilic cells of a front share of G. is observed at an acromegalia, giantism and leads in certain cases to development of adenoma of.
G.'s defeats cause disturbance of its function and various diseases. The clinicodiagnostic characteristic of some diseases and states arising at G.'s defeat is provided in the table.
make G.'s Tumours 7,7 — 17,8% of all intracranial new growths. Most often (apprx. 80%) benign adenomas meet, is more rare anaplastic (or dedifferentiated) and adenocarcinomas, and is extremely rare (1,2%) tumors of a back share of G. — a glioma, an ependymoma, a neuroepithelioma, an infundibuloma.
Adenomas of a front share of G. make a considerable part of intracranial tumors and often are the reason hypo - or a hyperpituitarism and a prelum of visual decussation. At the same time G.'s adenomas quite often are an accidental find during the opening. True adenomas differ from hyperplastic sites in iron in the big sizes (fig. 5). Also transitional forms between a small adenomatous small knot without capsule and typical adenoma of the large sizes meet. Makes certain difficulties differential patomorfol. diagnosis between adenoma and G. O cancer of a zlokachestvennost of tumors of G. judge by a structural atipizm, is more rare on their infiltrative growth and lack of the capsule. Intensive migration of beta cells from an intermediate part in a back share, edge it can be observed at hyperplastic reactions of gland, sometimes mistakenly take for infiltration of gland cancer cells.
G.'s adenoma meets at mature age at persons of both sexes more often. In process of growth adenoma can fill a cavity of the Turkish saddle, otdavlivat up its diaphragm and make impact on visual decussation (fig. 6) and a bottom of the third cerebral cavity, leading to emergence corresponding nevrol, and eye symptomatology. Adenoma can grow also towards a wedge-shaped bosom (fig. 7). At survey fabric of a tumor soft, serovatokrasny color, sometimes with sites of very small calcifications or cystous regeneration. Existence of hemorrhages in fabric of a tumor is characteristic of adenoma. On gistol, to symptoms of adenoma of G. subdivide on chromophobic, acidophilic and basphilic (fig. 8 — 10). The mixed adenomas consisting of chromophobic and chromophilic cells meet. Chromophobic adenomas, then basphilic acidophilic less often are most often observed. Chromophobic adenomas consist of cells of a polygonal form with a hyperchromic kernel and very faintly painted cytoplasm. Often they are located in the form of islands with indistinct borders. Allocate the embryonal type of a structure of chromophobic adenomas which is characterized by existence of chromophobic cells of a cylindrical form. Such cells are located perivaskulyarno, their long axis is directed perpendicularly to a gleam of capillaries and creates peculiar sockets (fig. 8). Chromophobic adenomas can reach the big sizes and clinically proceed, as a rule, with symptoms of a prelum of the next nervous educations. Acidophilic (eosinophilic) adenomas differ in slower growth and often are followed by a hyperplasia of other closed glands (adrenal glands and thyroid) and disbolism (see. Acromegalia , Giantism ). At microscopic examination in fabric G. hypertrophied cells of an oval form (fig. 9) in which cytoplasm specific granularity is painted by eosine or oranzhy in purple-red color are observed. Kernels of cells are rich with chromatin, occasionally with figures of a mitosis. Hormonal and active adenomas, in particular at an acromegalia, often consist of cells with scantier eosinophilic granularity and chromophobic elements. Basphilic adenomas (fig. 10) form from large cells with intensively painted granularity of cytoplasm in dark red color at reaction to glycoproteins Schiff's reactant or aniline blue. Basphilic adenomas differ in the slow growth and rather small sizes. Among endocrine diseases basphilic adenoma meets at Itsenko's disease more often — Cushing.
In special group allocate anaplastic adenomas and adenocarcinomas which are malignant tumors of. Considerable cellular polymorphism (fig. 11), more dense arrangement of cells, the centers of a necrosis, numerous figures of a mitosis and the expressed infiltrative growth are characteristic of anaplastic adenomas. An adenocarcinoma — one of seldom met forms of malignant pituitary adenomas. More expressed signs of a zlokachestvennost are inherent in it: infiltrative growth with early innidiation and corresponding a wedge, manifestations, lack of the capsule, sites of hemorrhages. The tumor consists of the polymorphic randomly located cells. Ugly, huge multinucleate cells meet. In some cases in a tumor in general there are no ferruterous structures.
The tumor of a residual pituitary pocket containing cystous cavities (fig. 12) also concerns to group of tumors of pituitary area — cranyopharyngioma (see).
The clinic of tumors of G. depends on character and localization, and also on the speed of their development. At most of patients of a tumor are shown by three groups of syndromes (Girsh's triad): 1) symptom complex of endocrine and exchange disturbances (adiposagenital syndrome, acromegalia, disorders of sexual function etc.); 2) rentgenol, the symptom complex which is characterized by hl. obr. increase in the sizes of the Turkish saddle; 3) symptom complex neuroophthalmolum. disturbances (primary atrophy of optic nerves and change of fields of vision as a bitemporal hemianopsia). In rather late stages of a disease with the expressed growth of a tumor over the Turkish saddle in a wedge, a picture there are also these or those symptoms of damage of a brain which generally depend on size, the direction and growth rate of a tumor.
G.'s tumor in an early stage of a disease grows in a cavity of the Turkish saddle and is quite often shown only by endocrine disturbances; on roentgenograms expansion of the Turkish saddle is visible. Gradually increasing, the tumor can extend down, filling a cavity of a wedge-shaped bosom. Extending up, the tumor lifts a diaphragm of the Turkish saddle, stretching it, gets through an infundibulyarny opening in a diaphragm, becoming intrasellyarny. In this stage of its growth visual disturbances which degree depends on specific features of an arrangement and blood supply of optic nerves and their decussation join.
At further development the part of a tumor growing up, displacing and deforming visual decussation, visual tracts, causes the corresponding symptoms. The big tumors extending out of limits of the Turkish Saddle make impact on tanks of a brain, ventricular system, basal departments of frontal and diencephalic and temporal structures, a trunk, cranial nerves, the main vessels of the basis of a brain, quite often being implemented into cavernous sine, destroy bones of a base of skull. However there are not always expressed anatomic changes caused by a tumor.
Diagnosis of tumors of G., including recognition like adenoma, its sizes and the direction of growth, is based on the analysis a wedge, pictures in dynamics and these additional methods of researches, generally kraniografiya (see), tomographies (see) and X-ray contrast methods of a research (see. Encephalography ).
Characteristic kraniografichesky symptoms of intrasellyarny tumors of G. are changes of the Turkish saddle: increase in its sizes, change of a form, deepening of a bottom, destruction, thinning, straightening of a back of a saddle (fig. 13). Often G.'s tumor goes beyond the Turkish saddle. In such cases depending on the preferential direction of growth of a tumor additional symptoms appear. The tumor growing kpered thins the front inclined shoots, one of them is more often that indicates spread of a tumor towards the most changed inclined shoot. The intrasellyarny tumor growing kzad causes destruction, and sometimes and total disappearance of a dorsum sellae. Destruction can extend also to area of a slope of an occipital bone. From top to bottom the growing G.'s adenomas sharply deepen a bottom of the Turkish saddle, narrow a gleam of a wedge-shaped bosom. In such cases contours of sharply lowered bottom of the Turkish saddle merge with a bottom of a wedge-shaped bosom, and its gleam disappears, or the low-intensive shadow of the tumor pressing in her cavity is visible. Especially it is necessary to emphasize presence of two or mnogokonturnost of a bottom of the Turkish saddle at spread of a tumor out of its limits. More convincing data at spread of a tumor out of the Turkish saddle can be obtained on side tomograms with median and sagittal and paracentral (on both sides from the centerline) cuts. As a rule, at even very big adenomas of G. there are no secondary signs of a prelum of bones of a calvaria. It allows to differentiate G.'s adenomas with other tumors of area of the Turkish saddle (cranyopharyngiomas, dermoids, tumors of a bottom of the third ventricle) which are followed by the expressed symptoms of intracranial hypertensia on kraniogramma.
At cranyopharyngiomas and dermoids on kranio-and tomograms limy inclusions in a gleam of the Turkish saddle come to light and it is far beyond its limits both in fabric of the tumor, and in walls of its capsule.
At G.'s adenomas limy inclusions, as a rule, do not meet, only sometimes they can be noted at the patients who were exposed to a roentgenotherapy. For specification of the sizes, the directions of preferential growth of a tumor of G. and other tumors of a diencephalon apply various contrast methods of a research.
Cerebral angiography (see) it is especially informative with a growth of a tumor of a kpereda, up and lateralno from the Turkish saddle. At verkhnezadny spread of a tumor the pnevmotsisternoentsefalografiya, especially in a combination with a tomography in median and sagittal and direct (at the level of the Turkish saddle) projections gives the most valuable diagnostic characters at vertical position of the patient. Topografoanatomichesky relationship of a tumor of area of the Turkish saddle with ventricular system of a brain comes to light at ventrikulografiya (see) or pnevmotomotsisternoentsefalografiya.
The main indications to surgical treatment of tumors of G. are progressing oftalmonevrol. the disturbances accruing on intensity headaches (preferential the basal and shell type — so-called phrenic), and also symptoms of a prelum a tumor of surrounding formations of a brain.
V. M. Ugryumov (1969), A. P. Romodanov (1971), etc. consider that at G.'s tumors Ophthalmolum is better to make operative measures even before development. frustration and others nevrol, symptoms.
Proceeding from anatomo-topographical features of pituitary area and options of preferential distribution of new growths, apply two essentially various surgical accesses to G.: ekstrakranialny (transsphenoidal) and intracranial (subfrontal).
Transsphenoidal access at tumors was for the first time provided by H. Schloffer in 1907. In the subsequent various modifications of transsphenoidal access, the majority of which are of only historical interest, were offered. The greatest distribution was gained by transsphenoidal interventions by the techniques offered by Girsh (O. of Hirsch) and X. Cushing in 1909. At transnasal transsphenoidal access to G. make a submucosal resection of a nasal partition through nasal openings with the subsequent removal of a part of a share and trepanation of a wedge-shaped bosom and a front wall of the Turkish saddle (Girsh). Oronazalny transsphenoidal access to G. (Cushing) differs only in way of achievement of a kostnokhryashchevy skeleton of a nasal partition, approach the last after a section and flaking of a mucous membrane in the field of an alveolar shoot of an upper jaw under an upper lip. At this access protection of an operational wound from an infection from a nasal cavity is reached. To use of transsphenoidal accesses the intrasellyarny arrangement of a new growth, the antelocation of visual decussation complicating an oncotomy intracranial access, advanced age and a serious general condition of patients are considered as the main indications.
The oncotomy of G. intracranial (intracranial) access for the first time was carried out by V. Horsley in 1906. However the greatest distribution got the access offered by N. V. Bogoyavlensky in 1911 in various modifications. Position of the patient on spin-faced up. The section of skin is carried out in frontal area along the line of growth of hair. In a frontal bone form rectangular nadkostnichno on the right - the bone rag, the sizes to-rogo usually do not exceed 4 x 6 cm (fig. 14). By the time of opening of a firm meninx the volume of a brain is reduced by means of dehydrating agents (Mannitolum, urea, lasixum). The firm meninx is opened with a linear section parallel to a superciliary arch. Then the pole of a frontal lobe is gradually displaced by kzad and up, crossing an olfactory path. After opening of the tank of decussation and aspiration of cerebrospinal liquid approach anterosuperior department of a tumor, edges often is under the displaced up, intense diaphragm of the Turkish saddle. The tumor at the same time usually moves apart optic nerves in the parties and displaces up and kzad visual decussation. The diaphragm of the Turkish saddle after coagulation of vessels is cut semicircular or crucial incision. Delete with an acute spoon a tumor. Carefully delete parts of a tumor from side departments of a cavity of the Turkish saddle since the tumor quite often destroys an internal wall of a cavernous sine and its damage can cause intensive venous bleeding. When the sine is completely filled with tumoral masses, as much as possible to delete a tumor especially dangerously since possibly damage of the intra cavernous site of an internal carotid artery and third cranial nerves. After an oncotomy make whenever possible broad excision of a diaphragm of the Turkish saddle. This manipulation is carried out carefully since the diaphragm can be soldered to a lower surface of a hiazma and at the same time the vessels which are taking part in its blood supply can be damaged.
At G.'s adenomas with considerable distribution out of limits of the Turkish saddle use bilateral subfrontal access with bandaging and crossing of an upper sagittal sine in front department and a section of a falx cerebri. It allows to increase the angle of operational action and to improve the review of area of the Turkish saddle, and to thereby increase radicalism of intervention.
At big tumors the purpose of operation can be considered reached when optic nerves and their decussation are exempted from a prelum by a tumor. Exclusively careful stop of bleeding from a cavity of the Turkish saddle is necessary.
The most terrible postoperative complication — development of a syndrome gipotalamo - pituitary and adrenal insufficiency which is shown by heavy disturbances of cardiovascular activity, breath, thermal control, and also neurodystrophic changes of internals. For the purpose of the warning of this complication to patients carry out replaceable hormonal therapy, to-ruyu begin in the preoperative period and continue after operation depending on individual reactivity of an organism of patients to steroid drugs.
According to a number of authors, the postoperative lethality in many respects depends on the size of a tumor, degree of its prevalence out of limits of the Turkish saddle. At tumors in the Turkish saddle it makes 2%. At big tumors the lethality reaches 33 — 35%. The over-all postoperative mortality at G.'s tumors makes 16,4% (A. L. Dukhin, 1974). Main reasons it: disturbance of breath, acute development arterial hypo - either hypertensia and a hyperthermia or bleeding with formation of the subshell or intracerebral bleedings.
In most cases in the postoperative period improvement or stabilization of sight is observed, headaches stop.
At G.'s tumors are developed and stereotaxic operations are applied (see. Stereotaxic neurosurgery ), carried out by preferential transsphenoidal access using cryosurgical and radio surgical techniques (see. Cryosurgery , Radio surgery ).
Stereotaxic methods krio-and radio surgical interventions on G. apply also for the purpose of a hypophysectomy, i.e. to destruction or G.'s removal at the patients suffering from hormonedependent malignant new growths (a breast cancer, a prostate cancer, etc.), and also at some endocrine diseases (severe forms of a diabetes mellitus, etc.).
Radiation therapy of tumors of G. is applied along with surgical methods. At an arrangement of a tumor in the Turkish saddle when into the forefront endocrine frustration act and there are no disturbances from sight or they progress slowly, remote radiation therapy is effective in 78 — 85% of cases. With a growth of a tumor out of the Turkish saddle remote radiation therapy is shown after neurosurgical intervention. At the same time at 80% of patients within five years and at 42% within ten years a recurrence of tumors is not observed [Jackson (N. of Jackson), 1958].
It is more preferable to carry out radiation therapy of tumors of G. on gamma devices using pendular radiation at the angle of swing 180 — 270 °. The field of radiation of 4x4 cm in size is located over an orbit, the plane of rotation is oriented at an angle 25 — 35 ° to a base plane that is reached by reduction of a chin to a breast at position of the patient on spin. In the first days apply small single doses (in the center no more than 25 — 50 I am glad). In case of lack of reaction to radiation the single dose in the center is increased to 200 I am glad. The general dose in 30 — 35 days of treatment makes apprx. 5000 is glad. The good effect is rendered also by an interstitial beta-ray therapy, at a cut directly into fabric of a tumor of G. implant a source 90Y (see. Yttrium ).
As a result of treatment endocrine disturbances (especially acromegalic syndrome), and also a headache at a long and persistent shell pain syndrome decrease.
Table. The clinicodiagnostic characteristic of some diseases and states arising at damage of a hypophysis
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A. I. Abrikosov, B. V. Alyoshin; F. M. Lyass, Ya. V. Patsko, 3. N. Polyanker, A. P. Popov, A. P. Romodanov (pathology); author of tab. F. M. Egart.