From Big Medical Encyclopedia

POLYCYSTIC DYSPLASIA OF KIDNEYS (grech, poly is a lot of + kystis a bubble; a dysplasia) — the disturbance of development of a renal parenchyma leading to emergence of cysts, which is combined with extrarenal anomalies and pathology of an urinary system. Allocate a polycystosis, a multicystosis and a microcystosis of kidneys.

The item of dative is recognized much more often at children, than at adults, observed in the form of an independent form of pathology or at a number of malformations, including at tuberous sclerosis (see), Gippel's diseases — Lindau (see. Gippelya — Lindau a disease ), Fankoni's nefronoftiza (see. Fankoni nefronoftiz ). The acquired cystous transformation of kidneys is observed at patients later hemodialysis (see).

In an experiment P. is received by dative at laboratory animals at administration of Prednisolonum, diphenylamine and other nephrotoxic substances. In P.'s development by dative the condition of outside cytomembranes and desmosomes of a canalicular epithelium, and also its papillary hyperplasia creating microobstructions has importance.

Mikropreparata of kidneys at a polycystic dysplasia: and — a polycystosis of a parenchyma of a kidney (1 — the cysts divided by poorly expressed layers of connecting fabric); — a multicystosis of a parenchyma of a kidney (1 — cysts, 2 — accurately expressed connecting fabric dividing cysts); coloring hematoxylin-eosine, x 60.

Polycystosis (polycystic disease of kidneys) — hereditarily the caused nephropathy with a bilateral cystosis of a part of rather developed parenchyma — collective tubules and tubules of nephron (fig., a). Allocate a polycystosis at children's age which is inherited on autosomal recessively type (has various manifestations at children of different age), and a polycystosis at adults (see. Kidneys ), inherited on autosomal dominantly type.

At a polycystosis of kidneys at newborns the increased kidneys are palpated, frequent vomiting is observed, the child does not put on weight. Concentration ability of kidneys is reduced (see. Kidneys ), in blood — the increased contents urea (see) and residual nitrogen (see. residual nitrogen ). Increase in the ABP is possible. Renal failure (see) accrues, and 80% of children die during the first 4 weeks of life, the others — aged about one year.

At a section research of a kidney of the big size with a set of the cysts bordered with a flat or cubic epithelium, the cystosis covers apprx. 90% of a parenchyma, hl. obr. collective tubules of both kidneys, and also it is often observed in a liver, lungs, pancreatic and thymic glands.

The polycystosis of kidneys at children of early and advanced age is essentially similar to a polycystosis of newborns on character morfol, changes, but in kidneys remains from 40 to 75% of the unimpaired parenchyma, than and explain much less heavy displays of a disease and its duration up to several years. However further the sizes of kidneys decrease at the expense of an intersticial sclerosis (see). The renal failure progresses, abnormal liver functions at the same time accrue.

At a polycystosis of kidneys occupy about 10% of volume of a parenchyma of a kidney teenagers of a cyst, into the forefront in a wedge, to a picture of a disease abnormal liver functions act and portal hypertensia (see), caused by periportal fibrosis. Further progressing of changes of a renal parenchyma owing to cystous dilatation of the functioning nephrons, a compression and a sclerosis of renal fabric is observed. Balls can be hypertrophied, but in process of progressing of disturbances of the fabric surrounding cysts develops hyalinosis (see). All this causes late development of a chronic renal failure.

Multicystosis (cystous dysplasia of kidneys) — an inborn malformation of kidneys, most often unilateral (at newborns — bilateral is more often) and segmented, caused by a delay of formation, a cystosis and a sclerosis of a parenchyma of a metanephros of a fruit; it is usually connected with pathology of urinary tract. The dysplasia of kidneys is explained by an embriofetopatiya, but she is also option of family and hereditary syndromes multiple malformations (see).

At a unilateral multicystosis the renal parenchyma is developed insufficiently, a kidney small (aplastic, hypoplastic); however most often a kidney voluminous, in it there are cysts of various size divided by layers and tyazha of connecting fabric (fig., b). Division of a parenchyma into layers is erased, in it the amount of nephrons is sharply reduced. Gistol, as markers of a dysplasia serve primitive channels, tubules and balls of fetalis type, ochazhka of a metaplastic cartilage are found less often. Renal cysts usually are not reported with urinary tract.

In a clinical picture various symptoms of a malformation of kidneys and urinary tract dominate. The disease quite often comes to light at infection of urinary tract, carrying out urography (see), an angiography (see. Renal angiography ), renografiya (see. Renografiya radio isotope ), scanning of kidneys (see. Scanning ).

During timely removal of the affected kidney the forecast favorable, it worsens at accession of arterial hypertension.

Microcystosis (inborn nephrotic syndrome) — the special hereditary cystous transformation of the developed parenchyma of both kidneys caused by dilatation and dysfunction of a proximal part of tubules of nephron it is frequent against the background of immunol, the conflict between an organism of mother and a fruit. The disease occurs at children of the first year of life (see. Nephrotic syndrome ).

Forecast serious, use of immunodepressants slows down progressing of a disease.

Diagnosis. The main diagnostic methods of all forms P. of dative are X-ray radiological and functional and biochemical. Decrease in functions of kidneys on tubular type, deformation of pyelocaliceal cavities, changes of the sizes and a configuration of kidneys, and also filling of cysts with a contrast agent (is found at a polycystosis) or the seeming lack of a kidney (at a multicystosis).

Treatment Item of dative symptomatic and surgical; at a chronic renal failure carry out hemodialysis (see), further it is shown renal transplantation (see).

Bibliography: Ignatova M. S. and Veltishchev Yu. E. Hereditary and inborn a nephropathy at children, page 5, L., 1978; Kozhukhova O. A. iklem-bovsky A. I. Morphological manifestations of disturbances of a differentiation of renal fabric at children, Arkh. patol., t. 41, century 10, page 6, 1979; Pytel A. Ya. About cystous gemmations and their classification, Urol, and nefrol., No. 1, page 3, 1975; Evan A. P., Gardner K. D. a. Bernstein J. Polypoid and papillary epithelial hyperplasia, Kidney int., v. 16, p. 743, 1979; Krem-p i e n B. R i t z E. Acquired cystic transformation of the kidneys of haemodia-lysed natients, Virchows Arch. path. Anat. A, Bd 386, S. 189, 1980; Nephrology, ed. by J. Hamburger a. o., N. Y., 1979; Potter E. L. a. Craig J. M. Pathology of the fetus and the infant, L., 1976; Royer P. e. a. N£phrologie p6diatri-que, P., 1973; Rubin M. Bar-r a t t T. M. Pediatric nephrology, p. 337, Baltimore, 1975.

A. I. Klembovsky.