Congential Abnormalities Of The Kidney/cystic Kidneys Flashcards Preview

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Flashcards in Congential Abnormalities Of The Kidney/cystic Kidneys Deck (18)
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Agenesis of the kidney

Can be unilateral or bilateral
- unilateral is less common but is compatible with life
- bilateral is more common and incompatible with life

*if unilateral, the normal kidney will hypertrophy*


Hypoplasia of the kidney

Can be bilateral or unilateral
- it’s observed in low birth weight infants and increases risk of CKD and renal failure lifelong


Ectopic kidneys

Due to ectopic foci developing

Kidneys can form anywhere but usually are around the pelvic brim at or around the renal arteries
- can increase likelihood of kinking or torsions of the ureters which increases risk of obstruction and bacterial infections


Horseshoe kidney

Found in 1:500/1000 people

Kidneys fuse either around the upper (10%) or lower poles (90%)

Usually wraps around the IMA and forms a U

Doesnt necessarily cause any symptoms and usually is benign


Double/ bifid ureters

Are usually unilateral and benign

Caused by either splitting completely of the metanephrogenic bud or bifid splitting before penetrating the renal mesenchyma
- double ureters almost always have associated distinct renal pelvis


Ureteropelvic junction obstruction

Congenital disorder that is most common cause of hydronephrosis in infants and children
- 20% bilateral and more often occur in males


Vesicoureteral reflux (VUR)

**Most common and serious congenital anomaly of the bladder**
- also chronic VUR is the most common cause of chronic pyelonephritis

**incompetence of the VUR is an important cause of ascending UTIs**


Diverticula of the bladder

Vary in size from < 1 cm-10 cm

Most are acquired, however congenital ones may be due to focal failure of development of normal musculature or UT obstruction in fetal development

Can be asymptomatic but also not since they are sites for urinary stasis and predisposition of infections


Exstrophy of the bladder

Developmental failure of the anterior wall of the abdomen so the bladder now peaks out as an opened sac

Have increased risk of infections and adenocarinoma for lifetime
- surgically correctable in infancy


Urachal anomalies

1) Fistula = connects the bladder to the umbilicus
- allows for urine to excrete out of umbilicus

2) sinus = blind end pouch on the umbilicus
- does not show urine excretion of umbilicus
- no direct communication to bladder

3) cyst = blind end pouch as well that is connected to the median umbilical ligament
- does not show urine excretion
- no direct communication to bladder
- * cysts can develop into cancers (make up 20-40% of bladder adenocarcinoma)


Epispadias/ hypospadias

Hypospadias = ventral urethral opening of the penis
- more common (1:300)
- will results in urinary tract obstruction
- shows increased risk of ascending UTIs

Epispadias = dorsal urethral opening of the penis


Autosomal dominant polycystic kidney disease (ADPKD)

Adult form of cystic kidney disease
- causes symptoms and renal failure usually starting at 40-60 yrs of age

Common condition
- 1/400 - 1/1000 live births
- accounts for 5-10% of ESRD

Causes multiple expanding cysts in both kidneys and liver as well as increased berry aneurysms in the cerebral vasculature and 35% increases in MVP

Clinical features
- hematuria
- flank pain
- UTIs
- renal stones
- unexplained HTN

Defective gene is PKD1/2 on chromosome 16 which encodes polycystin-1 and/or 2
- 85% = PKD-1 and polycystic-1 defects
- 15% = PKD-2 and polycystic-2 defects
- ** this is why cystic kidney diseases are considered ciliopathy processes

Will kill eventually, but takes a long time, usually around 60s
- death is from uremia or HTN complications


Autosomal Recessive Polycystic kidney disease

Has 4 subcategories depending on time of presentation and whether hepatic fibrosis/lesions are present or not
- perinatal (most common)
- neonatal (most common)
- infantile
- juvenile

Caused by PKHD1 gene mutations occur chromosome translation 6p21-p23
- causes defective fibrocystin which leads to cystic development

Causes clinical features of renal and/or hepatic failure in childhood.
- if the children dont die = hepatic fibrosis and liver issues for life


What are the 3 subsets of nephronophthisis?


Familial juvenile nephronophthisis (most common)

Renal-retinal dysplasia (15%)

**are all autosomal recessive**



**Is the most common cause of ESRD in children and young adults**

- polyuria and polydipsia always presents 1st
- growth retardation
- anemia
- extrarenal associations (retinal dystrophy, cerebellar abnormalities and ocular motor abnormalities)
**should be strongly expected in children that have unexplained renal failure and chronic tubulointersitial nephritis on kidney biopsy**

Shows defective genetic defects on NPHP1-11 and JBTS2/3/9/11 genes
- causes defective nephrocystins which produces corticomedullary cysts and small kidneys


Adult onset medullary cystic disease

Autosomal dominant pattern of transmission
- mutations in genes MCKD1/2 which casues corticomedullary cysts and small kidneys

Causes chronic renal failure that begins in child hood and progresses to end-stage kidney disease in adult life


Nephronophthisis morphology

Gross = Kidneys look small and have granular surfaces with cortexmedullary junction cysts

Histology = cysts that are flattened cuboidal epithelium and are surrounded by inflammatory cells/fibrosis tissue


Acquired cystic disease

Pretty much only seen in dialysis-associated in ESRD patients

Shows numerous cortical and medullary renal cysts that measure between 0.1-4 cm (wide range)
- contains clear fluid and often contains calcium oxalate crystals as well

Most are asymptomatic but can cause hematuria when the cysts bleed
- ***there is a 12-18x increased risk of RCC with patients who have this (7% of all dialysis patients get this in 10 yrs)***