In the neonatal period it is important to differentiate
hydronephrosis from cystic disease of the kidney, since treatment of these entities differ. Early surgery in
hydronephrosis may be indicated to salvage kidney function. We studied a group of 29 infants with renal
cysts or
hydronephrosis. In 10 cases some doubt about diagnosis remained after thorough diagnostic imaging. These infants were examined using percutaneous
puncture of the kidney to verify the suspected diagnosis of multicystic renal disease. The studies were performed using
local anesthesia and sedation. Ultrasonography was used for
puncture and contrast medium was injected during fluoroscopy. The
cysts communicated in 7 out of 10 cases, and a true renal pelvis was never seen. Irregular tubular structures joining the
cysts were identified in 7 cases and seem to be characteristic of the
multicystic dysplastic kidney. One instance of the hydronephrotic type of
multicystic kidney was found at surgery. Large size of the
cysts can make diagnosis difficult. Percutaneous
puncture was successful and gave the diagnosis in all cases. No complications ensued.