for Undergraduate Medical Students (MBBS)

1. Renal system
Dr.CSBR.Prasad, MD.,

2. Congenital anomalies

3. Congenital anomalies
• Agenesis of the kidney
• Hypoplasia
• Ectopic kidney
• Horseshoe kidney
• Multicystic renal dysplasia

4. 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

5. Agenesis of the kidney

6. Agenesis of the kidney

7. Potter facies

8. Potter facies

9. 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

10. Hypoplasia

11. Hypoplasia

12. Ectopic kidneys
• Above the pelvic brim
• In the pelvis
• They are of normal size and functioning
Complications:
• Due to their position ureters become tortuous
> get kinked > obstruction to urinary flow >
UTI

13. Ectopic kidneys

14. 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

15. Horseshoe kidneys

16. Horseshoe kidneys

17. Multicystic renal dysplasia
• Due to abnormal metanephric differentiation
• Other associations:
– Ureteropelvic obstruction
– Ureteral agenesis
– Atresia
– Other lower urinary tract anomalies

18. 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

19. Multicystic renal dysplasia

20. Multicystic renal dysplasia

21. Multicystic renal dysplasia

22. Multicystic renal dysplasia

23. Cystic diseases of the Kidney

24. 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

25. 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

26. 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

27. 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

28. 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

29. AD (Adult) polycystic kidney disease
(ADPKD)
• ADPKD is a systemic disorder
– Cysts are also seen in other organs

30. 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

31. AD (Adult) polycystic kidney disease

32. AD (Adult) polycystic kidney disease

33. AD (Adult) polycystic kidney disease

34. AD (Adult) polycystic kidney disease
Clinical 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

35. AD (Adult) polycystic kidney disease
(ADPKD)
Death due to:
• CHD / Hypertensive heart disease 40%
• Infections 25%
• Ruptured berry aneurysm
• Hypertensive intracranial hemorrhage

36. AR (Childhood) polycystic kidney disease
(ARPKD)
Subcategories:
– Depending on the time of presentation
– Presence of associated hepatic lesions
1. Perinatal
2. Neonatal
3. Infantile &
4. Juvenile
1 & 2 are most common, serious manifestations,
rapid renal failure

37. 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

38. AR (Childhood) polycystic kidney disease
(ARPKD)
Morphology:
Gross:
• Kidneys are enlarged
• Smooth external surface
• c/s small cysts in the cortex and medulla – sponge
kdney
Microscopy:
• Cylindrical saccular dilatations of collecting ducts
• Cysts are lined by cuboidal cells
• Liver cysts 100% (Biliary duct cysts)

42. AR (Childhood) polycystic kidney disease
(ARPKD)
Complications:
– Congenital hepatic fibrosis
– Portal hypertension
– Splenomegaly

43. Congenital hepatic fibrosis

44. END