This document discusses congenital malformations of the kidney. It is divided into three sections: abnormalities in renal tissue amount, anomalies in position and shape, and cystic diseases. Cystic diseases are further classified as multicystic renal dysplasia and polycystic kidney disease. Polycystic kidney disease occurs in two forms - an adult autosomal dominant form and a rare infantile autosomal recessive form. The adult form typically manifests between ages 30-50 with back pain, bleeding, infections and hypertension, while the infantile form causes renal failure in early childhood.

1. The KIDNEY – 2
CONGENITAL
MALFORMATIONS
DR. ROOPAM JAIN
PROFESSOR & HEAD, PATHOLOGY

2. CONGENITAL
MALFORMATIONS

3. CONGENITALMALFORMATIONS
• Malformations of the kidneys are classified into 3 broad groups:
• I. Abnormalities in amount of renal tissue :
• anomalies with deficient renal parenchyma (e.g. unilateral or bilateral
renal hypoplasia) or with excess renal tissue (e.g. renomegaly,
supernumerary kidneys).
• II. Anomalies of position, form and orientation :
• renal ectopia (pelvic kidney), renal fusion (horseshoe kidney) and
persistent foetal lobation.
• III. Anomalies of differentiation :
• ‘cystic diseases of the kidney’

4. CYSTIC DISEASES OF KIDNEY
• Cystic lesions of the kidney may be congenital or acquired, non-
neoplastic or neoplastic.
• Majority of these lesions are congenital non-neoplastic.
• Cystic lesions in the kidney may occur at any age, extending from foetal
life (detected on ultrasonography) to old age.
• Their clinical presentation may include: abdominal mass, infection,
respiratory distress (due to accompanied pulmonary hypo
plasia), haemorrhage, & neoplastic transformation

5. Classification of cystic lesions of the kidney

6. Cystic
diseases
of kidney

7. I. Multicystic Renal Dysplasia
• Renal dysplasia is the most common form of cystic renal disease in the
newborn and infants.
• The condition may occur sporadically or maybe familial and part of a
syndrome of other anomalies.
• It is commonly associated with obstructive abnormalities of the ureter
and lower urinary tract such as obstruction of pelviureteric junction
(PUJ), ureteral atresia and urethral obstruction

8. I. Multicystic Renal Dysplasia
CLINICAL FEATURES
• Unilateral renal dysplasia is frequently discovered in newborn or infants
as a flank mass. Often, renal dysplasia is associated with other
congenital malformations and syndromes such as VSD,
tracheoesophageal fistula, lumbosacral meningomyelocele and Down’s
syndrome.
• Th e prognosis of unilateral renal dysplasia following removal of the
abnormal kidney is excellent while bilateral renal dysplasia results in
death in infancy unless renal transplant is done

9. II. Polycystic Kidney Disease
• disorder in which major portion of the renal parenchyma is conver
ted into cysts of varying size.
The disease occurs in two forms:
• A. An adult type inherited as an AD disease
• B. An infantile type inherited as an AR disorder

10. A. ADULT POLYCYSTIC KIDNEY DISEASE
• Adult (autosomal dominant) polycystic kidney disease (ADPKD) is
relatively common (incidence 1:400 to 1: 1:1000) and is the cause of
end-stage renal failure in approximately 4% of haemo dialysis patients.
• AD with mutation in PKD gene: mutation in PKD-1 gene located on
chromo some 16 in over 85% cases (ADPKD-1) while remainder 15%
cases have mutation in PKD2 gene located on chromosome 4 (ADPKD-
2).
• Family history of similar renal disease may be present.
• Th e true adult polycystic renal disease is always bilateral and diff use.
• symptoms appear in adult life, mostly between the age of 30 and 50
years.

11. Polycystic kidney disease

12. A. ADULT POLYCYSTIC KIDNEY DISEASE
• The condition may become clinically apparent at any age but most
commonly manifests in 3rd to 5th decades of life.
• Th e most frequent and earliest presenting feature is a dull-ache in
the lumbar regions
presenting complaints are
• haematuria or passage of blood clots in urine,
• renal colic,
• hypertension,
• urinary tract infection and
• progressive CRF with polyuria and proteinuria.

13. Adult (AD)
polycystic
kidney disease
(ADPKD)
The kidney is enlarged and heavy. Sectioned surface shows loss of
demarcation between cortex and medulla and replacement of the entire
renal parenchyma by cysts varying in diameter from a few millimeters to 4-
5 cm. These cysts are not communicating with the pelvicalyceal system.
The renal pelvis and calyces are distorted due to cystic change

14. B. INFANTILE POLYCYSTIC KIDNEY DISEASE
• Th e infantile (autosomal recessive) form of polycystic kidney disease
(ARPKD), less common (incidence 1:20,000 births).
• It is transmitted as an AR trait
• Th e condition occurs due to a mutation in chromosome 6—6p21,
PKHD1 (polycystic kidney and hepatic disease 1).
• It is invariably bilateral.
• The age at presentation may be perinatal, neonatal, infantile or
juvenile, but frequently serious manifestations are present at birth and
result in death from renal failure in early childhood.

15. Polycystic kidney
disease

16. B. INFANTILE POLYCYSTIC KIDNEY DISEASE
MORPHOLOGIC FEATURES
• the kidneys are bilaterally enlarged with smooth external surface and
retained normal reniform shape.
• Cut surface reveals small, fusiform or cylindrical cysts radiating from the
medulla and extend radially to the outer cortex.
• sectioned surface of the kidney sponge-like appearance

17. B. INFANTILE POLYCYSTIC KIDNEY DISEASE
CLINICAL FEATURES
• The clinical manifestations depend on age of the child.
• In severe form, the gross bilateral cystic renal enlargement may
interfere with delivery.
• In infancy, renal failure may manifest early.
• Almost all cases of infantile polycystic kidney disease have associated
multiple epitheliumlined cysts in the liver or proliferation of portal bile
ductules.
• In older children, associated hepatic changes develop into what is
termed congenital hepatic fibrosis which may lead to portal
hypertension and splenomegaly

18. Contrasting features of AD (adult) and AR (infantile) polycystic
kidney disease (ADPKD versus ARPKD)