congenital anomalies csbrp

Renal system

Dr.CSBR.Prasad, MD.,

Congenital anomalies

Congenital anomalies

• Agenesis of the kidney• Hypoplasia• Ectopic kidney• Horseshoe kidney• Multicystic renal dysplasia

Agenesis of the kidney

• Bilateral agenesis– Incompatible with life– Associated with other congenital anomalies– Still born infants

• Unilateral agenesis– Compatible with life– Compensatory hypertrophy of opposite kidney– Chronic kidney disease may ensue

Agenesis of the kidney

Agenesis of the kidney

Potter facies

Potter facies

Hypoplasia

• Small kidneys:– Bilateral• Renal failure in early childhood

– Usually unilateral• Most commonly this is due to ACQUIRED -

vascular, infectious causes• Congenital: few nephrons, no scars• Acquired: few nephrons, scarring

Hypoplasia

Hypoplasia

Ectopic kidneys

• Above the pelvic brim• In the pelvis• They are of normal size and functioningComplications:• Due to their position ureters become tortuous

> get kinked > obstruction to urinary flow > UTI

Ectopic kidneys

Horseshoe kidneys

• Fusion can occur either in the upper or lower poles– 90% fusion in the lower poles– 10% fusion in the upper poles

• Middle portion is anterior to the great vessels• 1 in 500 to 1000 autopsies• Complications:– Ureteral obstruction & associated complications

Horseshoe kidneys

Horseshoe kidneys

Multicystic renal dysplasia

• Due to abnormal metanephric differentiation• Other associations:– Ureteropelvic obstruction– Ureteral agenesis– Atresia– Other lower urinary tract anomalies

Multicystic renal dysplasia• Gross:

– Unilateral / bilateral– Enlarged, irregular and multicystic

• Histologically:– Undifferentiated mesenchyme– Cartilage– Immature collecting ductules– Abnormal lobar organization– Cysts are lined by flattened epithelium– Nephrons may be normal But, collecting ducts are immature

Multicystic renal dysplasia

Multicystic renal dysplasia

Multicystic renal dysplasia

Multicystic renal dysplasia

Cystic diseases of the Kidney

Cystic diseases of the Kidney

• Heterogeneous– Hereditary– Developmental– Acquired

• Imporatance:– They are common– Presents a diagnostic problem

• Occasionally confused with Malignancy– Genetic cystic diseases are a cause for Chronic kidney

disease

AD (Adult) polycystic kidney disease(ADPKD)

• AD with high penetrance• Multiple expanding cysts destroy the renal

parenchyma• Chronic renal failure• 1 in 500 to 1000 live births• 5-10% of cases of CRF

AD (Adult) polycystic kidney disease(ADPKD)

• Bilateral• Initially involves only portions of nephrons in

cystic degeneration, hence,• Renal functions are preserved for a long time• Presentation in 4th & 5th decade of life

AD (Adult) polycystic kidney disease(ADPKD)

Genetics:• AD with high penetrance• Requires mutation in both alleles of PKD gene• Products of PKD genes are located in the cilia or renal tubules• PKD1 (16p13.3) – Encodes 460kD polycystin-1, transmembrane protein– Cell-Cell & Cell-Matrix interactions– most common (85%)– End stage renal disease by 53yrs

• PKD2 (4q21)– Encodes polycystine-2, integral membrane protein, Ca+

channel– End stage renal disease by 69yrs

AD (Adult) polycystic kidney disease(ADPKD)

Pathogenesis:• Abnormal CILIA-CENTROSOME complex of tubular epithelial

cells• it’s a CILOPATHY

– Epithelium of tubules contain single non-motile cilium of 2-3µm long• Fuction:

– Mechanoceptor, monitors the changes in fluid flow– They also regulate ion flux – Regulate cell polarity and proliferation

• Hypothesis: defects in mechanosensing, Ca+ flux and signal transduction underlie cyst formation

AD (Adult) polycystic kidney disease(ADPKD)

• ADPKD is a systemic disorder– Cysts are also seen in other organs

AD (Adult) polycystic kidney disease(ADPKD)

Morphology:– Gross: • Both kidneys are enlarged• May attain enormous size, 4kgs each• External surface shows cysts 3-4cms in diameter• No normal intervening parenchyma

– Microscopy:• Cysts may have variable lining epithelia as they may

arise in different portions of renal tubules• There may be little normal intervening renal tissue• Cysts filled with serous fluid / brown turbid fluid

AD (Adult) polycystic kidney disease

AD (Adult) polycystic kidney disease

AD (Adult) polycystic kidney disease

AD (Adult) polycystic kidney diseaseClinical features:• Usually asymptomatic until renal failure ensue• Hemorrhages / progressive dilatation of the cysts may

produce pain• Dragging sensation in the abdomen• Hematuria• Proteinuria• Polyuria• Hypertension• Other associated anomalies:

– 40% liver cysts– Splenic / pancreatic / lung cysts– Intracranial berry aneurysms– MVP

AD (Adult) polycystic kidney disease(ADPKD)

Death due to:• CHD / Hypertensive heart disease 40%• Infections 25%• Ruptured berry aneurysm• Hypertensive intracranial hemorrhage

AR (Childhood) polycystic kidney disease(ARPKD)

Subcategories:– Depending on the time of presentation– Presence of associated hepatic lesions

1. Perinatal2. Neonatal3. Infantile &4. Juvenile 1 & 2 are most common, serious manifestations,

rapid renal failure

AR (Childhood) polycystic kidney disease(ARPKD)

Genetics:• PKHD1 Chr 6p21-p23• Encodes 447kD integral membrane protein

fibrocystine• They are located in the cilium• They are associated with collecting duct and

biliary duct differentiation

AR (Childhood) polycystic kidney disease(ARPKD)

Morphology:Gross:• Kidneys are enlarged• Smooth external surface• c/s small cysts in the cortex and medulla – sponge

kdneyMicroscopy:• Cylindrical saccular dilatations of collecting ducts• Cysts are lined by cuboidal cells• Liver cysts 100% (Biliary duct cysts)

AR (Childhood) polycystic kidney disease(ARPKD)

Complications:– Congenital hepatic fibrosis– Portal hypertension– Splenomegaly

Congenital hepatic fibrosis

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