2. RENAL CYSTS
• Fluid filled spaces within the kidney
• May involve cortex or medulla or both
• May be unilateral or bilateral
• May be unilocular or multilocular
• May be congenital or acquired
• May be sporadic or genetically determined
• Clinical significance may be trivial or grave
3. SIMPLE CYSTS
• Simple Renal Cysts Extremely common as age
advances
• Incompletely understood pathogenesis
• Commonly associated with scarred kidneys
• Asymptomatic with normal renal function
• May be solitary/multiple/unilateral/bilateral
• Generally unilocular, round to oval of varying sizes
Usually 1-5 cm.
• Smooth surface
• Incidental finding
5. Adult Polycystic kidney
• Autosomal dominant
– PKD1 (polycystin-1) on Chromosome 16
– 90% of cases
– PKD2 (polycystin-2) on chromosome 4, 10% of cases
• Multiple expanding cysts
• Destruction of renal parencyma
• 10% of chronic renal failure cases
• PREVALANCE=1 in1000
• Usually B/L
6. • Clinical:
– Present in the 4th decade OR older children
– Flank pain
– Mass
– intermittent hematuria
– Hypertension
– Infection
– Association: berry aneurysm of brain, cysts in liver,
pancreas, others. Diverticular disease.
– Slow progression
– End stage kidney at age of 50y
7. • Diagnosis: US, CT
• Treatment: aimed at preventing complications,
preserving renal function; family education
• Episodes of gross haematuira should be
conservatively managed: bed-rest, analgesics,
hydration
• In the case of UTI: trimetoprim-
sulfamethoxazole, ciprofloxacin should be given
( they enter the cyst fluid),
• therapy of hypertension
• Ser creatinine should be followed yearly
• In end stage: renal replacement therapy
8. Childhood polycystic kideny
ARPKD
• Autosomal recessive, chromosome 6
• Infants and childhood
• renal collecting tubules and ducts become
cystically dilated and numerous small cysts form
in the renal cortex and medulla bilaterally.
• Severe forms present early and have a poor
prognosis.
• Incidence of 1 in 10000– 40000
• Association
– Multiple cysts in the liver
– Congenital hepatic fibrosis
9. • Prenatal USS demonstrates
• oligohydramnios (amniotic fluid <200mL) and
large, ‘bright’, homogeneously
hyperechogenic kidneys which can cause
obstructed labour and respiratory problems
(secondary to pulmonary hypoplasia).
10. Clinical symptoms
abdominal mass, UTI, failure to thrive,
• Infants may develop fatal uraemia and re-
spiratory failure;
• older children present with renal failure,
hypertension, and portal hypertension.
• Most develop end- stage renal failure by
adulthood, requiring haemodialysis,
nephrectomy (to control hypertension), and
sub-sequent renal transplantation
11. Non genetic
• Multicystic dysplastic kidney
• kidney is dysplastic and non- functioning due
to failure of induction of the metanephric
blastema by the ureteric bud, with immature
dysplastic stroma and non- communicating
cysts of various sizes.
• The proximal ureter is atretic in about 66%.
12. INCIDENCE
• unilateral MCKD is one in 4000, with a
♂:♀ratio of 2:1.
• Bilateral disease occurs in 10% of cases and is
incompatible with life
• Presentation
• detected on antenatal USS (20wk gestation).
A 34wk antenatal USS is performed to assess
for contralateral anomalies.
13. Clinical types and associated disorders
• simple (contralateral kidney is normal on USS)
complicated (contralateral side is abnormal).
Unilateral disease is associated with VUR or
PUJO in the contralateral kidney in 70%.
A ureterocele will be associated with MCKD in
10% of cases.
14. Management
• Postnatal renal tract USS is performed at 1wk after birth (beware
PUJO with huge dilatation if multiple cysts with a large central cyst
are seen on USS).
• Simple MCDK
• No prophylactic antibiotics.
• repeat USS and DMSA renogram are performed at 6wk to confirm
there is no renal function in the MCDK.
• Affected kidneys (especially those <6cm) tend to involute. Most
can be treated conservatively with surveillance of growth, BP, urine
analysis, and USS follow- up
• surgical removal for MCDK
• >6cm (which tend to grow),
• any solid component, hypertension, symptoms, or parental
preference.
15. • Complicated MCDK
• Prophylactic antibiotics are started at birth.
• Postnatal USS and MAG3 renogram are performed to
investigate obstruction (i.e. contralateral PUJO).
• MCUG and DMSA renogram are performed to exclude
reflux.
• Risks
• The risk of developing hypertension or Wilms’ tumour with
MCDK is rare, and routine nephrectomy to prevent the
development of these conditions is no longer
recommended.
• Follow- up of BP, growth, proteinuria, and renal tract USS is
recommended
16. ACQUIRED RENAL CYSTIC DISEASE
• Secondary to end-stage renal disease
• prolonged dialysis ( 9 months -7 yrs.)
• Kidneys are generally small but may be normal
or even enlarged.
• Neoplastic changes are common (Occasional
adenoma, and renal cell carcinoma)
