Purpose: The objective of this study is to evaluate natural history of multicystic kidney (MCK) and renal function of the contralateral kidney.
Methods: We analyzed 18 children (7 boys and 11 girls) with unilateral MCK. The sizes of cysts were investigated by ultrasonography. Urinary beta 2-microgloblin (beta 2 m), alpha 1-microgloblin (alpha 1 m) and N-acetyl-beta-D-glucosaminidase (NAG) and albumin were determined as markers of tubular and glomerular damage. The renal function was evaluated by 99m Tc-dimercaptosuccinic acid (99 m Tc-DMSA) renal uptake rate.
Results: Nephrectomy was performed in 2 children. In 14 (87.5%) of 16 cases who were followed conservatively, the size of cysts was spontaneously reduced by 1-18 months (mean 6.4). Neither hypertension nor malignancy from the affected kidney has been observed in follow-up periods of 6-63 months. One patient had minor degree of contralateral ureteral dilatation which resolved spontaneously. Lower DMSA uptake rate of contralateral kidney was demonstrated in 63% (10/16). Markers of tubular damage were abnormally high in these patients.
Conclusion: From these results, the most appropriate management of MCK is conservative with ultrasonic monitoring. Long-term follow-up testings with special care on contralateral renal function will be necessary because the overload to the contralateral healthy kidney may have already occurred during infancy and cause focal glomerulosclerosis and renal failure in future.