1. Multicystic dysplastic kidney 1/2000 Common cause of abdominal mass in newborn Contralateral VUR:15% Contralateral hydronephrosis:5-10%

2. Sonography: kidney replaced by multiple cyst of varying size, no communication, no identifiable parenchyma. Renal scan: no function Annual followed up Nephrectomy: abdominal mass, any cyst enlarged, hypertension, stromal core increased in size

3. Multicystic dysplastic kidney Simple Complex: combined with other GU abnormality (duplication of the collecting system, dilation of the ureter or renal pevis, posterior urethral valve, neurogenic bladder, uretocele, cryptorchism)

4. Simple MCDK had an incidence of UTI similar to in children without MCDK(5%) Complex MCDK : increased risk of UTI: 28% Bilateral or unilateral MCDK with associated GU abnormality place the patietn at the incrased risk of UTI independent of VUR Clinical course and outcome for children with MCDK, Pedriatr Nephrol(2000)

5. Eur J Pediatr(1998) Multicystic kidney shrink in the first 2 years of life Contralateral kidney maintain a normal renal function as a consequence of progressive compensatory hypertrophy

6. Clinical feature of unilateral MCKD in child Eur J Pediatr(1998) 40/204: nephrectomy 164/204; conservative tx Slight renal function impairement No difference in the number of complication in two group.

7. Prophylaxis antibiotics? simpleComplex Total p ’ t2114 F/U mean(yr)5.48.4 range(yr)0.1-221.9-23 VCUG53 VUR42 Prophylaxis ABx 2(10%)7(50%)

8. outcome simpleComplex Total p ’ t2114 UTI14 Chronic renal insuficiency 04 ESRD03