Renal System - Abnormalities

Embryology - 2 Dec 2023        Expand to Translate
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ICD-11 Structural developmental anomalies of the urinary system

LB30 Structural developmental anomalies of kidneys - LB30.0 Renal agenesis or other reduction defects of kidney | LB30.1 Renal dysplasia | LB30.2 Congenital single renal cyst | LB30.3 Renal tubular dysgenesis | LB30.4 Oligomeganephronia | LB30.5 Accessory kidney | LB30.6 Fusion anomaly of kidneys | LB30.7 Ectopic or pelvic kidney | LB30.8 Medullary sponge kidney | LB30.9 Multicystic renal dysplasia LB31 Structural developmental anomalies of urinary tract - LB31.0 Congenital hydronephrosis | LB31.1 Congenital primary megaureter | LB31.2 Foetal lower urinary tract obstruction | LB31.3 Exstrophy of urinary bladder | LB31.4 Congenital diverticulum of urinary bladder | LB31.5 Duplication of urethra | LB31.6 Congenital megalourethra | LB31.7 Megacystis-megaureter | LB31.8 Atresia or stenosis of ureter | LB31.9 Agenesis of ureter | LB31.A Duplication of ureter | LB31.B Malposition of ureter | LB31.C Congenital absence of bladder or urethra | LB31.D Congenital vesico-uretero-renal reflux KC01 Congenital renal failure A severe irreversible decline in the ability of kidneys to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism which existed at, or often before, birth. GB41 Nephrotic syndrome "A condition characterised by severe proteinuria, greater than 3.5 g/day in an average adult. The substantial loss of protein in the urine results in hypoalbuminaemia and generalised oedema. There is also usually hyperlipidaemia. Other manifestations of glomerular disease may be present. There are many possible causes and renal histological appearances. Possible complications include vascular thrombosis, infections, malnutrition and renal failure.

Introduction

Obstructive Defect of the Renal Pelvis

Horseshoe kidney

There are many different forms of renal development abnormalities associated with kidney, ureters, bladder and urethra. There are many genetic disorders associated with failure or abnormal renal development.

Prenatal diagnosis of obstructive and renal agenesis/dysgenesis disorders are also important for early reproductive decisions by the parents. For example, with bilateral renal agenesis, failure of both kidneys to development, is not compatible with fetal/neonatal survival.

"Horseshoe" kidney is the historic name for renal fusion, where the two kidneys are joined together usually by a single pole.

Because of their close developmental association, often described as the urogenital system, there can be an associated genital abnormalities.

There are also a range of branchiootorenal spectrum disorders (branchiootorenal syndrome and branchiootic syndrome) where both renal and auditory development are affected (for review see ).

Postnatally, newborn oxidative stress is thought to be involved in the progression of renal failure.

System Abnormalities

Abnormality Links: abnormal development | abnormal genetic | abnormal environmental | Unknown | teratogens | ectopic pregnancy | cardiovascular abnormalities | coelom abnormalities | endocrine abnormalities | gastrointestinal abnormalities | genital abnormalities | head abnormalities | integumentary abnormalities | musculoskeletal abnormalities | limb abnormalities | neural abnormalities | neural crest abnormalities | placenta abnormalities | renal abnormalities | respiratory abnormalities | hearing abnormalities | vision abnormalities | twinning | Developmental Origins of Health and Disease |  ICD-11 Historic Embryology   1915 Congenital Cardiac Disease | 1917 Frequency of Anomalies in Human Embryos | 1920 Hydatiform Degeneration Tubal Pregnancy | 1921 Anencephalic Embryo | 1921 Rat and Man | 1966 Congenital Malformations

Some Recent Findings

Mouse renal ureteropelvic junction obstruction

Embryology and Morphological (Mal)Development of Ureteropelvic Junction "Kidney parenchyma and collecting system arise from two different embryologic units as a result of a close interaction between them. Therefore, their congenital abnormalities are classified together under the same heading named CAKUT (congenital abnormalities of the kidney and urinary tract). The pathogenesis of CAKUT is thought to be multifactorial. Ureteropelvic junction obstruction (UPJO) is the most common and most investigated form of CAKUT. Despite years of experimental and clinical research, and the information gained on the embryogenesis of the kidney; its etiopathogenesis is still unclear. It involves both genetic and environmental factors. Failure in development of the renal pelvis, failure in the recanalization of ureteropelvic junction, abnormal pyeloureteral innervation, and impaired smooth muscle differentiation are the main proposed mechanisms for the occurrence of UPJO. There are also single gene mutations like AGTR2, BMP4, Id2 proposed in the etiopathogenesis of UPJO." Ectopias of the kidney, urinary tract organs, and male genitalia "The most frequent anomaly of the urogenital tract is a simple renal ectopia with one organ lying in the pelvis. Crossed renal ectopia is a less common condition in which the ectopic kidney is located on the opposite side of the midline from the ureteral insertion in the urinary bladder. The cause of both types of renal ectopia is the arrest or failure of the kidney ascent from the pelvic to the lumbar position. Whereas an accelerated ascent leads to a subdiaphragmal or intrathoracic ectopic position, an ectopic ureter can be defined as one that does not drain into the trigonum vesicae. The ectopic orificium can be located situated in the bladder neck and urethra as well as somewhere in the genital area.Exstrophy of the urinary bladder is not a complete ectopia. Because the abdominal wall and the anterior part of the bladder wall are lacking, the bladder mucosa grows directly into the skin. The complex exstrophy of the bladder and intestine corresponds to a cloacal exstrophy, in which the bladder is split in two halves on either side of the gut portion. Testicular ectopia refers to the location of the testis in a position outside of its normal course of descent.Prostatic ectopia does not refer to the wrong location of the entire organ, but to a scattered group of prostate glands, which are mostly found in the submucosal part of the urinary bladder or proximal urethra. Other described locations are the intestinal wall, anus, pericolic fat tissue, spleen, seminal vesicle, testis, and cervix uteri.The associated ectopic penis, scrotum, and penoscrotal transposition are the least common and probably the absolutely most unknown malformations of the male genitalia. The ectopic penis and scrotum are located in the perineum, whereas in the transposition the penis lies above the scrotum."

More recent papers

This table allows an automated computer search of the external PubMed database using the listed "Search term" text link. This search now requires a manual link as the original PubMed extension has been disabled. The displayed list of references do not reflect any editorial selection of material based on content or relevance. References also appear on this list based upon the date of the actual page viewing. References listed on the rest of the content page and the associated discussion page (listed under the publication year sub-headings) do include some editorial selection based upon both relevance and availability. More? References | Discussion Page | Journal Searches | 2019 References | 2020 References Search term: Abnormal Renal Development | Renal Fusion | Horseshoe Kidney | Polycystic Kidney Disease | Congenital Nephrotic Syndrome] Triad Syndrome |

Older papers

These papers originally appeared in the Some Recent Findings table, but as that list grew in length have now been shuffled down to this collapsible table. See also the Discussion Page for other references listed by year and References on this current page. Outcome after prenatal diagnosis of congenital anomalies of the kidney and urinary tract "Congenital anomalies of the kidney and urinary tract are common findings on fetal ultrasound. The aim of this prospective observational study was to describe outcome and risk factors in 115 patients born 1995-2001. All prenatally diagnosed children were stratified into low- and high-risk group and followed postnatally clinically and by imaging at defined endpoints. ...Our study revealed a good prognosis in the majority of these children, in particular with prenatally low risk, i.e. isolated uni- or bilateral hydronephrosis, and revealed oligohydramnios and postnatal bilateral anomalies as risk factors for a non-favourable outcome, defined as need of surgery, persistent anomalies with impaired renal function, end stage renal failure or death." Urothelial Defects from Targeted Inactivation of Exocyst Sec10 in Mice Cause Ureteropelvic Junction Obstructions "Most cases of congenital obstructive nephropathy are the result of ureteropelvic junction obstructions, and despite their high prevalence, we have a poor understanding of their etiology and scarcity of genetic models. The eight-protein exocyst complex regulates polarized exocytosis of intracellular vesicles in a large variety of cell types. Here we report generation of a conditional knockout mouse for Sec10, a central component of the exocyst, which is the first conditional allele for any exocyst gene. Inactivation of Sec10 in ureteric bud-derived cells using Ksp1.3-Cre mice resulted in severe bilateral hydronephrosis and complete anuria in newborns, with death occurring 6-14 hours after birth." Congenital urological anomalies diagnosed in adulthood "Despite worldwide availability of prenatal ultrasound, many patients are diagnosed in adult life with congenital anomalies such as ureteropelvic junction obstruction (UPJO), undescended testicle (UDT), ureterocele, hypospadias, vesicoureteral reflux (VUR) and primary obstructing megaureter (POM)." Etv4 and Etv5 are required downstream of GDNF and Ret for kidney branching morphogenesis "Mice lacking both Etv4 alleles and one Etv5 allele show either renal agenesis or severe hypodysplasia, whereas kidney development fails completely in double homozygotes. We identified several genes whose expression in the ureteric bud depends on Etv4 and Etv5, including Cxcr4, Myb, Met and Mmp14. Thus, Etv4 and Etv5 are key components of a gene network downstream of Ret that promotes and controls renal branching morphogenesis."

Australian Statistics

Statistics - Top Ten

Australian Data 1981-92

The ten most frequently reported birth defects in Victoria between 2003-2004.

1. Hypospadias
2. Obstructive Defects of the Renal Pelvis or Obstructive Genitourinary Defects
3. Ventricular Septal Defect
4. Congenital Dislocated Hip
5. Trisomy 21 or Down syndrome
6. Hydrocephalus
7. Cleft Palate
8. Trisomy 18 or Edward Syndrome - multiple abnormalities of the heart, diaphragm, lungs, kidneys, ureters and palate 86% discontinued.
9. Renal Agenesis/Dysgenesis - reduction in neonatal death and stillbirth since 1993 may be due to the more severe cases being identified in utero and being represented amongst the increased proportion of terminations (approximately 31%).
10. Cleft Lip and Palate - occur with another defect in 33.7% of cases.

Obstructive Renal Pelvis Defect

Renal outflow obstruction

Obstructive Renal Pelvis Defect (obstructive defects of the renal pelvis, uteropelvic junction obstruction, pelvo-uterero junction obstruction) is a term describing a developmental renal abnormality due to partial or complete blockage of the drainage of the kidney pelvis requiring surgical correction.

The blockage during development can be due to failure of recanalization of the outflow tract.

The blockage can have several anatomical causes including:

1. ureter twisting or bending
2. ureter compression by a blood vessel
3. malformations of the muscular wall

The blockage leads to an accumulation of urine in the affected region, with several potential effects: nephron damage from compression (hydronephrosis); decreased urine output leading to lack of amniotic fluid (oligohydramnios); respiratory development effects due to the lack of amniotic fluid. The most common type of obstruction is at the uteropelvic junction (UPJ), between the junction of the ureter and the kidney. Blockage lower as the ureter enters the bladder, the ureterovesicular junction (UVJ), usually involves only one kidney and the back flow enlarges the affected ureter (megaureter).

Renal Agenesis or Dysgenesis

International Classification of Diseases - Renal Agenesis or Dysgenesis Anomalies

ICD-11 LB30 Structural developmental anomalies of kidneys LB30.0 Renal agenesis or other reduction defects of kidney - A series of conditions resulting in reduced kidney function including a congenital absence of both kidneys LB30.00 Renal agenesis - A condition where one or both kidneys does not form (or develop) in utero. (Potter's syndrome) LB30.1 Renal dysplasia - A condition characterized by abnormal development of one or both kidneys. LB30.2 Congenital single renal cyst - A single cyst in a kidney, noted in utero or from birth. No other structural abnormality of the kidney or urinary tract noted. LB30.3 Renal tubular dysgenesis - Abnormal renal development and kidney formation secondary to an underlying condition or exposure. LB30.4 Oligomeganephronia - Oligomeganephronic renal hypoplasia is a severe developmental defect of both kidneys characterized by a reduced number of nephrons (the functional unit of the kidney), hypertrophic glomeruli with diameters twice the normal size, hypertrophic tubules and thickening of Bowman's capsule, occurring in the absence of a urinary tract malformation. LB30.5 Accessory kidney LB30.6 Fusion anomaly of kidneys - The embryological, incomplete fusion of renal lobules and/or kidneys. LB30.60 Lobulated kidney - Any condition caused by incomplete fusion of the developing renal lobules during the antenatal period. This condition may be asymptomatic. LB30.61 Fused pelvic kidney - A condition caused by failure of the kidneys to correctly develop during the antenatal period. This condition is characterized by the presence of a single kidney, along the midline of the body. This condition may present with kidney stones, hydronephrosis, kidney infection, hematuria, or may be asymptomatic. Confirmation is through observation of a fused kidney by imaging. LB30.62 Horseshoe kidney - Horseshoe kidney is the most frequent renal fusion anomaly and is characterised by the union of the inferior poles of the two kidneys through an isthmus. Horseshoe kidney is in fact an anatomical anomaly rather than a disease, but it does lead to predisposition to certain conditions such as hydronephrosis, nephrolithiasis or pyelonephritis. One third of individuals with horseshoe kidney are asymptomatic, with the anomaly being discovered fortuitously during a radiological examination. Urogenital or renal vessel anomalies may be associated with the condition. For cases requiring treatment, various therapeutic approaches are available and choice of treatment depends on the associated pathology. LB30.7 Ectopic or pelvic kidney - A birth defect characterized by an abnormally positioned kidney; may be asymptomatic or result in urine blockage, infection or kidney stones. LB30.8 Medullary sponge kidney - A condition characterised by cystic or saccular dilatations of the medullary collecting ducts seen with radiocontrast filling. A predisposition to stones and associated often with renal tubular acidosis. There is no clear genetic predisposition. LB30.9 Multicystic renal dysplasia - A condition characterized by abnormal development of the kidney, specifically in which the abnormal kidney does not form a reniform structure but rather, a collection of non-communicating cysts, with no renal functional tissue.

Potter's syndrome or sequence is a rare condition (1 in 2000-5000) resulting in bilateral renal agenesis and occurs more frequently in primigravid mothers and more commonly in male offspring. At birth affected infants have a characteristic facial phenotype known as "Potter facies", named after Potter (1946) original description.

Renal agenesis. DTPA scan shows agenesis of the right kidney.

Unilateral renal absence is relatively common and may be asymptomatic. In the complete form, bilateral absence, the child is not viable and dies within a few days of birth.

Features associated with this anomaly are:

• Oligohydramnios
• Amnion nodosum (small warty amnion with accretions of squamous cells on the inner wall). This is tangible evidence for oligohydramnios.
• Facial deformities: This results from uterine moulding around the head. The ears are low slung and simple, the mandible is small, the nose flattened and the eyes exhibit Pre-epicanthic folds. This is a horseshoe shaped flap of skin from the upper lid to the cheek in front of the epicanthus. (Downs syndrome has an epicanthic fold). Note that the genesis is occasionally incomplete allowing survival (e.g.) Causal factors are largely unknown although there is some familial predisposition. There has been described a mutation in the enzyme, heparan sulfate 2-sulfotransferase, that generates a similar phenotype in the mouse.

Note that upper G.I.T. obstruction is associated with POLYHYDRAMNIOS whereas failure of fetal micturition is associated with OLIGOHYDRAMNIOS with consequent firm uterine moulding on the fetus, leading to facial, locomotor and palatal deformities.

Renal agenesis. I.V. pyelography showing right renal agenesis (or dysplasia) (>). The right hip dysplasia is also shown (>>).

Links: OMIM - Urogenital Adysplasia, Hereditary

Renal Fusion

A Horseshoe.

ICD-11 LB30.62 Horseshoe kidney - Horseshoe kidney is the most frequent renal fusion anomaly and is characterised by the union of the inferior poles of the two kidneys through an isthmus. Horseshoe kidney is in fact an anatomical anomaly rather than a disease, but it does lead to predisposition to certain conditions such as hydronephrosis, nephrolithiasis or pyelonephritis. One third of individuals with horseshoe kidney are asymptomatic, with the anomaly being discovered fortuitously during a radiological examination. Urogenital or renal vessel anomalies may be associated with the condition. For cases requiring treatment, various therapeutic approaches are available and choice of treatment depends on the associated pathology.

The less common renal fusions are LB30.60 Lobulated kidney and LB30.61 Fused pelvic kidney.

Also described as Horseshoe kidney. Fusion of the lower poles of the kidney. During migration from the sacral region the two metanephric blastemas can come into contact, mainly at the lower pole. The ureters pass in front of the zone of fusion of the kidneys. The kidneys and ureters usually function adequately but there is an increased incidence of upper urinary tract obstruction or infection. Some horseshoe variations have been described as having associated ureter abnormalities including duplications.

Renal fusion (pathology specimen)

Historic

Eisendrath DN Phifer FM and Culver HB. Horseshoe Kidney (1925) Ann Surg. 82(5): 735-64. PubMed 17865363

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  Horseshoe kidney with symmetric halves

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  Horseshoe kidneys with asymmetric halves.

• 

  Horseshoe kidneys with asymmetric halves.

• 

  Well marked fibrous isthmus joining the two halves.

• 

  Horseshoe kidney with superior isthmus.

• 

  Note unusual form of both pelves.

Boyden EA. Description of a horseshoe kidney associated with left inferior vena cava and disc-shaped suprarenal glands, together with a note on the occurrence of horseshoe kidneys in human embryos. (1931) Anat. Rec. 51(2): 187-211.

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  Fig. 1 Horseshoe kidney

• 

  Fig. 2 Horseshoe kidney

• 

  Fig. 9 Horseshoe kidney

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  Fig. 10 Horseshoe kidney

Renal-Adrenal Fusion

A rare anomaly of the upper pole of the kidney historically first described by Rokitansky in 1855. Intrarenal ectopic adrenal tissue can also occur and in such instances consist of adrenal cortical tissue with no adrenal medullary tissue. Other organ fusions can occur with splenogonadal fusion the most commonly reported.

Triad Syndrome

Also described as Prune Belly Syndrome.

The Triad is:

1. Agenesis of abdominal wall muscles
2. Bladder outflow obstruction
3. Bilateral undescended testes

The condition was first described by Frolichand then called "prune belly syndrome" as a descriptive, because the intestinal pattern is evident through the thin protruding abdominal wall in the infant.

Survival of the prune belly child depends on the number of functioning remaining nephrons at birth and the operability of the obstruction.

In some cases there are vestiges of muscle in the abdominal wall and it is not known whether this represents (a) destruction of muscle, or (b) failure of development of muscle. The causes of this malformation are little known, but maternal therapy with estrogens in the first trimester has been implicated frequently.

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  Hydronephrosis

• 

  Renal outflow obstruction

• 

  Prune belly

Polycystic Kidney Disease

Multicystic kidney

Multicystic kidney and histology

• diffuse cystic malformation of both kidneys
• cystic malformations of liver and lung often associated, Often familial disposition
• Two types
  • Infantile (inconsistent with prolonged survival)
  • Adult (less severe and allows survival)
• Autosomal dominant PKD disease - recently identified at mutations in 2 different human genes encoding membrane proteins (possibly channels)

Defects in the genes encoding PC1 or PC2 lead to aberrant gene transcription, cell proliferation, and ion secretion, which in turn result in the formation of fluid-filled cysts. As cysts balloon out from individual nephrons, their collective effect leads to the displacement of the normal renal parenchyma and the formation of a cyst-filled kidney with reduced functional capacity.

Cyst formation at the level of the cell, nephron, and kidney

Nephroblastoma (Wilms' Tumor)

Wilms tumor

• (nephroblastoma) Named after Max Wilms, a German doctor who wrote first medical articles 1899
• most common type of kidney cancer children
• WT1 gene - encodes a zinc finger protein
• Both constitutional and somatic mutations disrupting the DNA-binding domain of WT1 result in a potentially dominant-negative phenotype
• some blastema cells (mass of undifferentiated cells) persist to form a ‘nephrogenic rest’
• Most rests become dormant or regress but others proliferate to form hyperplastic rests
• any type of rest can then undergo a genetic or epigenetic change to become a neoplastic rest
• can proliferate further to produce a benign lesion (adenomatous rest) or a malignant Wilms’ tumour

Renal Cysts

The Bosniak classification system (I - IV) was designed to separate identified cystic renal masses by analysis of computed tomography (CT) features into surgical and nonsurgical categories. Named after Morton Bosniak, Yale University School of Medicine, the developer of this classification system.

1. Category I lesions are simple benign cysts showing homogeneity, water content, and a sharp interface with adjacent renal parenchyma, with no wall thickening, calcification, or enhancement.
2. Category II consists of cystic lesions with one or two thin (<=1 mm thick) septations or thin, fine calcification in their walls or septa (wall thickening > 1 mm advances the lesion into surgical category III) and hyperdense benign cysts with all the features of category I cysts except for homogeneously high attenuation. A benign category II lesion must be 3 cm or less in diameter, have one quarter of its wall extending outside the kidney so the wall can be assessed, and be nonenhancing after contrast material is administered.
3. Category IIF consists of minimally complicated cysts that need followup. This is a group not well defined by Bosniak but consists of lesions that do not neatly fall into category II. These lesions have some suspicious features that deserve followup to detect any change in character.
4. Category III consists of true indeterminate cystic masses that need surgical evaluation, although many prove to be benign. They may show uniform wall thickening, nodularity, thick or irregular peripheral calcification, or a multilocular nature with multiple enhancing septa. Hyperdense lesions that do not fulfill category II criteria are included in this group.
5. Category IV lesions with a nonuniform or enhancing thick wall, enhancing or large nodules in the wall, or clearly solid components in the cystic lesion. Enhancement was considered present when lesion components increased by at least 10 H.

Urorectal Septum Malformation

Urorectal septum malformation thought to be a deficiency in caudal mesoderm which in turn leads to the malformation of the urorectal septum and other structures in the pelvic region. Recent research has also identified the potential presence of a persistent urachus prior to septation of the cloaca (common urogenital sinus).

Clinically the condition is described as a urorectal septum malformation sequence (URSMS): female disorder of sexual development; ambiguous external genitalia; imperforate anus, vagina, and urethra; renal, colonic, and lumbosacral anomalies.

Renal Vascular Anomalies

There is an excellent recent 2010 review of renal vascular anomalies shown in adults using computed tomography. The images below are from that review.

Renal Arteries

Multiple renal arteries	Accessory renal artery

Renal Veins

Supernumerary right renal vein	Supernumerary right renal vein
Multiple right renal veins	Multiple right renal veins

Renal Vascular Anomalies: Multiple renal arteries | Accessory renal artery | Supernumerary right renal vein 1 | Supernumerary right renal vein 1 | Multiple right renal veins 2 | Multiple right renal veins 2 | Cardiovascular System Development

Bladder Exstrophy

ICD-11 LB31.3 Exstrophy of urinary bladder - Bladder exstrophy (or classic bladder exstrophy) is a congenital genitourinary malformation belonging to the spectrum of the exstrophy-epispadias complex and is characterized by an evaginated bladder plate, epispadias and an anterior defect of the pelvis, pelvic floor and abdominal wall.

Bladder_Exstrophy

• developmental abnormality associated with bladder development.
• origins appear to occur not just by abnormal bladder development, but by a congenital malformation of the ventral wall of abdomen (between umbilicus and pubic symphysis).
• There may also be other anomolies associated with failure of closure of abdominal wall and bladder (epispadias, pubic bone anomolies).

Bladder

• absent or small bladder - associated with renal agenesis.

Bladder Duplication

Bladder duplication

An extremely rare abnormality. This Magnetic Resonance Image (MRI) shows a complete bladder duplication with urethra duplication, diphallus, anorectal malformation and rightsided renal agensis with ipsilateral gonadal agenesisis. red arrow - collapsed right bladder blue arrow - distended left bladder orange arrow - midline septum yellow arrow - right phallus green arrow - left phallus

Ureterocele

The distal ureter balloons at the opening into the bladder and forms a sac-like pouch. Often associated with other ureter abnormalities.

Ureter and Urethra

International Classification of Diseases - Ureter and Urethra Anomalies

ICD-11 LB31 Structural developmental anomalies of urinary tract LB31.0 Congenital hydronephrosis - Congenital hydronephrosis is a renal urinary disease characterized by distension and dilation of the renal pelvis and calyces secondary to various congenital obstructive malformations of the kidneys and urinary tract that can evolve to renal atrophy. LB31.1 Congenital primary megaureter - Congenital primary megaureter is an idiopathic condition in which the bladder and bladder outlet are normal but the ureter is dilated to some extent. It may be obstructed, refluxing or unobstructed and not refluxing. LB31.2 Foetal lower urinary tract obstruction - A disease caused by partial or complete obstruction of the urethra, during the antenatal period. This disease can present with enlarged bladder, oligohydramnios, or pulmonary hypoplasia. Confirmation is through observation of the obstruction by imaging. LB31.5 Duplication of urethra - A condition caused by failure of the urethra to correctly develop during the antenatal period. This condition is characterized by the presence of a second passage from the bladder. This condition may present with double urinary stream, urination from the anus, or may be asymptomatic. Confirmation is through observation of a second urethra by imaging. LB31.6 Congenital megalourethra - A condition caused by failure of the penile corpora cavernosa and spongiosa to correctly develop during the antenatal period. This condition is characterized by dilatation of the penile urethra. This condition may present with poor stream, swelling of the penis, megacystis, oligohydramnios, renal failure, or pulmonary hypoplasia. LB31.7 Megacystis-megaureter - Megacystic-megaureter syndrome describes the presence of a massive primary non-obstructive vesicoureteral reflux and a large capacity, smooth, thin walled bladder due to the continual recycling of refluxed urine. Recurrent urinary infections are commonly associated with this condition. LB31.8 Atresia or stenosis of ureter - A condition caused by blockage or narrowing of the ureter due to failure to correctly develop during the antenatal period. This condition may present with bladder outlet obstruction, low amniotic fluid volume, pulmonary hypoplasia, megacystis, hydroureter, hydronephrosis, or renal dysplasia. LB31.9 Agenesis of ureter - A condition caused by failure of the ureter to develop during the antenatal period. Confirmation verification that one or more ureters are missing by imaging. LB31.A Duplication of ureter - A condition caused by failure of the ureter to correctly develop during the antenatal period, resulting in incorrect connection of the ureter to the kidney. This condition may present with ureteroureteral reflux, or ureteropelvic junction obstruction of the lower pole of the kidney in the case of incomplete duplication. Complete duplication may present with vesicoureteral reflux, ectopic ureterocele, or ectopic ureteral insertion. Confirmation is through observation of two ureters on one side by imaging. LB31.B Malposition of ureter - A condition caused by failure of the ureter to correctly develop during the antenatal period, resulting in partial or complete duplication of the ureter. This condition may present with hydronephrosis, urinary tract infection, or incontinence in females. Confirmation is through observation of an incorrectly positioned ureter by imaging. LB31.C Congenital absence of bladder or urethra - Any condition caused by failure of both the bladder and the urethra to develop during the antenatal period. This condition may result in fetal death, or sepsis and sever complications in cases of live births. LB31.D Congenital vesico-uretero-renal reflux - A condition caused by failure of the ureter to develop correctly during the antenatal period. This condition may present with urinary tract infection, or may be asymptomatic.

Ureteral duplication. Frontal radiograph from an intravenous urogram study shows bilateral complete ureteral duplication.

• Ureter - Duplex Ureter, ectopic ureter
  • Meyer-Weigert Rule - clinical term for the arrangement of the ureter in a completely duplicated renal system, the ureter from the upper renal pole enters the bladder more medially and caudally than the ureter from the lower renal pole.
• Urethra - Urethral Obstruction and Hypospadias

Ectopic and dilated left ureter (small arrows) inserting ectopically into the obstructed left hemivagina (asterisk) on MR imaging in a 17-year-old girl.

Male lower urinary tract obstruction can occur with posterior urethral valves (PUV) (incidence 1.6 to 2.1 per 10 000 births), an anterior urethral valves (AUV) are 25–30‐fold less common.

ICD-11 LB31.2 Foetal lower urinary tract obstruction - A disease caused by partial or complete obstruction of the urethra, during the antenatal period. This disease can present with enlarged bladder, oligohydramnios, or pulmonary hypoplasia. Confirmation is through observation of the obstruction by imaging.

See also Genital System - Abnormalities

Nephrotic Syndrome

podocyte filtration slits of glomerulus

(Congenital Nephrotic syndrome, lipoid nephrosis)

GB41 Nephrotic syndrome A condition characterised by severe proteinuria, greater than 3.5 g/day in an average adult. The substantial loss of protein in the urine results in hypoalbuminaemia and generalised oedema. There is also usually hyperlipidaemia. Other manifestations of glomerular disease may be present. There are many possible causes and renal histological appearances. Possible complications include vascular thrombosis, infections, malnutrition and renal failure.

Genetic Mutations include:

• nephrin - protein of the slit diaphragm of renal filtration barrier, located at the cell surface in the area between two podocytes. NPHS1 gene location 19q13.12, mutations in this gene are associated with Congenital Nephrotic Syndrome (Nephrotic syndrome). (More? renal abnormalities)

• podocin - protein of the slit diaphragm of renal filtration barrier, located at the cell surface in the area between two podocytes. NPHS2 gene location 1q25.2, mutations in this gene are associated with Congenital Nephrotic Syndrome (Nephrotic syndrome). (More? renal abnormalities)

References

Reviews

Chariatte V, Ramseyer P & Cachat F. (2013). Uroradiological screening for upper and lower urinary tract anomalies in patients with hypospadias: a systematic literature review. Evid Based Med , 18, 11-20. PMID: 22815315 DOI.

Woodhouse CR, Neild GH, Yu RN & Bauer S. (2012). Adult care of children from pediatric urology. J. Urol. , 187, 1164-71. PMID: 22335866 DOI.

Articles

Sinha R, Vasudevan A, Agarwal I, Sethi SK, Saha A, Pradhan S, Ekambaram S, Thaker N, Matnani M, Banerjee S, Sharma J, Singhal J, Ashraf S & Mandal K. (2020). Congenital Nephrotic Syndrome in India in the Current Era: A Multicenter Case Series. Nephron , 144, 21-29. PMID: 31655822 DOI.

Fernando MA, Creighton SM & Wood D. (2015). The long-term management and outcomes of cloacal anomalies. Pediatr. Nephrol. , 30, 759-65. PMID: 25217327 DOI.

Chowdhary SK, Kandpal DK, Sibal A & Srivastava RN. (2014). Management of complicated ureteroceles: Different modalities of treatment and long-term outcome. J Indian Assoc Pediatr Surg , 19, 156-61. PMID: 25197194 DOI.

Search Pubmed

Search Pubmed: Obstructive Renal Pelvis Defects | Renal Agenesis | hydronephrosis | Ureterocele

Historic

Vermooten V. Congenital cystic dilatation of the renal collecting tubules: A new disease entity. (1951) Yale J Biol Med. 23(6): 450–453. PMID 14836770

Smith E. and Strasberg A. Cysts of the genital ducts, Müllerian and Wolffian. (1946) Can Med Assoc J. 55(2): 119–121. PMID 20323857

Rusche CF and Bacon SK. Congenital renal anomalies: with special reference to horseshoe kidney. (1939) Cal West Med. 50: 344-348. PMID 18745137

Randall A. The origin and growth of renal calculi. (1937) Ann Surg. 105(6): 1009–1027. PMID 18745137

Morton JJ. and Jones TB. Obstructions about the mesentery in infants. (1936) Ann. Surg. 104: 864-891. PMID 17856875

Bell ET. Cystic disease of the kidneys. (1935) Am J Pathol. 11(3): 373–418. PMID 1910969

Oppenheimer GD. Polycystic disease of the kidney. (1934) Ann Surg. 100(6): 1136–1158. PMID 17856426

Abbott 1930 Anomalies of the genito-urinary tract. (1930) J. Can. Med. Assoc. -226.

Papin E. and Eisendrath DN. Classification of renal and ureteral anomalies. (1927) Ann Surg. 85(5): 735–756. PMID 17865673

Piersol GM. Polycystic disease of the kidney. (1927) Trans Am Climatol Clin Assoc , 43, 221-231. PMID 21408945

Hinman F. Gibson TE. and Kutzmann AA. Cysts of the Wolffian body. (1924) Ann Surg. 79(5): 762–769. PMID 17865035

Eisendrath DN. Congenital strictures and spiral twists of the ureters. (1917) Ann Surg. 65(5): 552–559. PMID17863705

Braasch WF. VIII. The clinical diagnosis of congenital anomaly in the kidney and ureter. (1912) 56, 726-737. PMID17862922

Eisendrath DN. Congenital malformations of the ureters. (1912) Ann Surg. 55(4): 571–592. PMID17862830

Spicer JE. Dystocia due to distension of the urinary bladder of the fœtus, with remarks on renal secretion in utero. (1909) Proc R Soc Med. 2(Obstet Gynaecol Sect): 1–24. PMID 19973800

Hamann CA. Spindle-shaped dilatations and tortuosity of the ureters in the fetus. (1902) J Med Res. 8(1): 125–127. PMID19971486

Terms

• anterior urethral valve - uncommon real abnormality.

• bilateral renal agenesis - (BRA) failure of both kidney development and is not compatible with life and is associated with oligohydramnios and pulmonary hypoplasia.

• CAKUT - congenital anomalies of the kidneys and urinary tract.

• Congenital Nephrotic Syndrome - (CNS, Nephrotic syndrome) rare kidney disorder characterized by heavy proteinuria, hypoproteinemia, and edema starting soon after birth. Most cases are caused by genetic abnormalities in the components of the glomerular filtration barrier, especially nephrin and podocin.

• cystic dysplasia - term used in renal dysplasia if cysts are present.

• Meyer-Weigert Rule - clinical term for the arrangement of the ureter in a completely duplicated renal system, the ureter from the upper renal pole enters the bladder more medially and caudally than the ureter from the lower renal pole.

• nephrin - protein of the slit diaphragm of renal filtration barrier, located at the cell surface in the area between two podocytes. NPHS1 gene location 19q13.12.

• Nephrotic Syndrome - (Congenital Nephrotic syndrome, CNS) rare kidney disorder characterized by heavy proteinuria, hypoproteinemia, and edema starting soon after birth. Most cases are caused by genetic abnormalities in the components of the glomerular filtration barrier, especially nephrin and podocin.

• podocin - protein of the slit diaphragm of renal filtration barrier, located at the cell surface in the area between two podocytes. NPHS2 gene location 1q25.2.

• posterior urethral valve - (congenital obstructing posterior urethral membrane) a common male renal abnormality (~1 in 10,000-25,000 live births) classified into 3 types. Membrane from mesonephric (Wolffian) duct origin forms of a thick, valve-like structure.

• renal agenesis - term for a complete absence of renal development.

• renal dysgenesis - term for several forms of abnormal kidney development, which includes aplasia, hypoplasia, dysplasia, and cystic disease.

• renal aplasia - term for a rudimentary kidney without any functional nephrons.

• renal hypoplasia - term for a small non-dysplastic kidney that has less than the normal number of calyces and nephrons.

• renal dysplasia - term for focal, diffuse, or segmentally arranged primitive structures, specifically primitive ducts, resulting from abnormal metanephric differentiation. There can also be non-renal elements present.

• renal adysplasia - term is used when aplasia and severe dysplasia are aspects of phenotypic spectrum.

• unilateral renal agenesis - (URA) failure of a single kidney development, often asymptomatic if not detected by prenatal screening.

Renal Terms
bladder exstrophy - A congenital malformation with bladder open to ventral wall of abdomen (between umbilicus and pubic symphysis) and may have other anomolies associated with failure of closure of abdominal wall and bladder (epispadias, pubic bone anomolies). blastema - Term used to describe a mass of undifferentiated cells. (More? Wilm's tumour) Bowman's capsule - (capsula glomeruli, glomerular capsule) Surrounds the glomerulus within the nephron with a vascular and urinary pole and is the beginning of the tubular component. Named in 1842 after Sir William Bowman (1816 – 1892) an English surgeon and anatomist. Brenner hypothesis - a clinical hypothesis that states, individuals with a congenital reduction in nephron number have a much greater likelihood of developing adult hypertension and subsequent renal failure. Developed in the 1980's by Barry Brenner at the Brigham and Women's Hospital, this also fits with the DOHAD hypothesis. (More? PubMed 3063284 | Barry Brenner) capillary loop - (C stage) The third stage in nephron development between 25-29 weeks. (stage sequence: V - S - C - M) Congenital Nephrotic Syndrome - see Nephrotic syndrome. (More? renal abnormalities) diabetes insipidus - The disorder is related to the hormone antidiuretic hormone (ADH, also called vasopressin) its synthesis, secretion, receptors and signaling pathway. In diabetes insipidus there is an excretion of large amounts (up to 30 litres/day) of a watery urine and an unremitting thirst. fenestrated capillary - Specialised capillaries containing circular pores (fenestrae) that penetrate the endothelium, may be closed by a thin diaphragm. glomerulus - The capillary network (tuft) within Bowman's capsule of the nephron enters at the vascular pole (afferent and efferent arteriole). hydronephrosis - (congenital hydronephrosis, Greek, hydro = water) A kidney abnormality due to partial or complete obstruction at the pelvi-ureteric junction. This leads to a grossly dilated renal pelvis causing extensive renal damage before birth. hyperplastic rests - In kidney development, embryonic blastema cells can persist and proliferate to form a pool of cells, which under either genetic or epigenetic influence can then change to become a neoplastic rest. Normally the majority of nephrogenic rests either regress or become dormant. juxtaglomerular cells - Cells located at the vascular pole that secrete renin and form a part of the juxtaglomerular complex. loop of Henle - Nephron region spanning from the proximal convoluted tubule to the distal convoluted tubule. Named after Named after Friedrich Gustav Jakob Henle (1809–1885) a German anatomist. macula densa - Columnar cell cluster appearing as a dense row of cell nuclei where the straight portion of the distal tubule contacts the glomerulus. Region also in close contact with the efferent and afferent arterioles of the glomerulus and involved in sodium chloride regulation. (More? image) maturation stage - (M stage) The forth stage in nephron development in infants aged 1-6 months. (stage sequence: V - S - C - M) mesangial cells - Cells in the nephron glomerulus that form the connective tissue giving structural support to podocytes and vessels. mesonephros - The second temporary stage of kidney development (pro-, meso-, meta-). The intermediate mesonephros develops and disappears with the exception of its duct, the mesonephric duct, which will form the male reproductive duct system. In males, the mesonephric tubules go on to form the ducts of the testis. In females, these degenerate. A few mesonephric tubules remain as efferent ductules in the male and vestigial remnants in the female. mesonephric duct - (= Wollfian duct) An early developing urogenital duct running the length of the embryo that will differentiate and form the male reproductive duct system. In females this duct degenerates (some remnants may remain associated in broad ligament). metanephros - The adult kidney, third stage of mammalian kidney (pro-, meso-, meta-) development within the intermediate mesoderm. metanephric cap - (metanephric blastema) The intermediate mesoderm which surrounds the ureteric bud and will contribute most of the adult nephron. multicystic kidney - There is no functional kidney tissue present in the kidney and it is replaced by a multilocular cyst. This is non-familial and is produced by atresia of a ureter and is always unilateral. neoplastic rest - In kidney development, a neoplastic rest can develop under either genetic or epigenetic influence from a hyperplastic rest, originating from an embryonic blastema cell. Normally the majority of nephrogenic rests either regress or become dormant. nephrin - protein of the slit diaphragm of renal filtration barrier, located at the cell surface in the area between two podocytes. NPHS1 gene location 19q13.12, mutations in this gene are associated with Congenital Nephrotic Syndrome (Nephrotic syndrome). (More? renal abnormalities) nephrogenic rest - Used to describe the embryonic blastema cells which persist and under either genetic or epigenetic can change to become a neoplastic rest. These neoplastic rests can develop postnatally as a benign form (adenomatous rest) or a malignant Wilm's tumour form. The rests are further characterised by the time of generation leading to different anatomical kidney locations: early intralobar nephrogenic rests (within the renal lobe) and late pelilobar nephrogenic rests (periphery of the renal lobe) nephron - (Greek, nephros = kidney) The functional unit of the adult kidney. nephros - (Greek, nephros = kidney) Term used to describe features associated with the kidney. (pronephros, mesonephros, metanephros, nephric, nephron, nephroblastoma). Nephrotic syndrome - (CNS, Nephrotic syndrome) rare kidney disorder characterized by heavy proteinuria, hypoproteinemia, and edema starting soon after birth. Most cases are caused by genetic abnormalities in the components of the glomerular filtration barrier, especially nephrin and podocin. (More? renal abnormalities) parietal layer - Cells of the outer of Bowman's capsule that form a simple squamous epithelium. The inner layer is the visceral layer. podocin - protein of the slit diaphragm of renal filtration barrier, located at the cell surface in the area between two podocytes. NPHS2 gene location 1q25.2, mutations in this gene are associated with Congenital Nephrotic Syndrome (Nephrotic syndrome). (More? renal abnormalities) podocyte - (visceral epithelial cell) kidney glomerulus cell forming the main component of the glomerular filtration barrier. (glomerular podocyte) Kidney epithelial cell type in the nephron (kidney functional unit) located in the glomerulus. Podocytes form the visceral layer of Bowman's capsule and are at the filtration barrier between capillary blood and the nephron tubular system and function to ultrafiltrate blood, and support glomerular capillary pressures. The differentiation of podocytes involves the formation of cellular foot processes and then the slit membrane. (More? image) podocyte specific proteins - podocalyxin, glomerular epithelial protein-1, podocin, nephrin, synaptopodin, and alpha-actinin-4), podocyte synthesized proteins (vascular endothelial growth factor and novH), transcription factors (WT1 and PAX2). pronephros - (Greek, pro = before) The first temporary stage of kidney development (pro-, meso-, meta-). This forms the kidney of primitive fish and lower vertebrates. Kidney development occurs within the intermediate mesoderm interacting with endoderm. In humans, this very rudimentary kidney forms very early at the level of the neck. It is rapidly replaced by the mesonephros, intermediate stage kidney, differentiating in mesoderm beneath. proteinuria - The abnormal presence of protein in the urine and an indicator of diesease including diabetic kidney disease (DKD, diabetic nephropathy). proximal tubule - Portion of the nephron duct between Bowman's capsule to the loop of Henle, divided into the proximal convoluted tubule (PCT) and the proximal straight tubule (PST). renal - (Latin, renes = kidney) Term used in relation to the kidney and associated structures (renal pelvis, renal artery) S-shaped body - (S stage) The second stage in nephron development between 20-24 weeks. (stage sequence: V - S - C - M) transitional epithelium - (urothelium) Histological term to describe the epithelium lining the ureters and urinary bladder. (More? image) trigone - refers to the urinary bladder triangular region formed by the two ureters and the urethra. ureter - The two ureters are hollow tubes that link the kidney and the bladder and carry urine. They develop from the ureteric bud and are lined by a transitional epithelium with an outer muscular wall. urethra - The single muscular tube that links and carries urine from the bladder to the exterior. In humans, the urethral length differs between the sexes (male longer, female shorter). vascular pole - The side of nephron Bowman's capsule where the afferent arteriole and efferent arteriole enter the glomerulus. image visceral layer - Cells (podocytes) of the inner of Bowman's capsule that form extremely complex shapes. Cytoplasm form a fenestrated epithelium around the fenestrated capillaries of the glomerulus. The outer layer is the parietal layer. vesicle stage - (V stage) The first stage in nephron development between 13-19 weeks. (stage sequence: V - S - C - M) urinary - Term used to describe all components of the kidney system including the bladder, ureters and urethra. urinary pole - The side of nephron Bowman's capsule where the proximal convoluted tubule starts. image urine - Term used to describe the liquid waste produced by the kidney, stored in the bladder and excreted from teh body through the urethra. urorectal septum - (URS) The structure which develops to separate the cloaca (common urogenital sinus) into an anterior urinary part and a posterior rectal part. Wilms' tumour - A form of kidney/renal cancer (nephroblastoma) named after Dr Max Wilms who first described the tumor. This childhood kidney cancer is caused by the inactivation of a tumour suppressor gene (BRCA2) or Wilms tumor-1 gene (Wt1) and is one of the most common solid tumors of childhood, occurring in 1 in 10,000 children and accounting for 8% of childhood cancers. Wt1 also required at early stages of gonadal development. (More? OMIM - Wilm's tumour | Dr Max Wilms) Wilms' tumor 1-associating protein - (WTAP) protein expressed in extraembryonic tissues and required for the formation of embryonic mesoderm and endoderm. Wolffian duct - (= mesonephric duct, preferred terminology), runs from the mesonephros to cloaca, differentiates to form the male vas deferens and in the female regresses. Named after Caspar Friedrich Wolff (1733-1794), a German scientist and early embryology researcher and is said to have established the doctrine of germ layers. (More? Caspar Friedrich Wolff)
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Cite this page: Hill, M.A. (2023, December 2) Embryology Renal System - Abnormalities. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Renal_System_-_Abnormalities

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