ABSTRACT. Objective. To document the involution rate and long-term results of management of multicystic dysplastic kidney.Materials and Methods. Data were collected retrospectively for all 23 infants (16 boys) with multicystic dysplastic kidney who were treated at our center over the last 19 years (1977)(1978)(1979)(1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995). The diagnosis was based on prenatal ultrasound in 18 patients and on palpable abdominal mass in 5, and confirmed in all patients by postnatal ultrasound and radioisotope scan. Voiding cystography was performed in 18 patients to exclude vesicoureteral reflux. Mean follow-up was 46 months (range, 3 months to 5 years) and included serum creatinine measurements and renal ultrasonography.Results. Two groups of patients were identified. Ten (43.6%) with other urologic abnormalities (group A) and 13 patients without other urologic abnormalities (group B). Vesicoureteral reflux was observed in 4 patients. Nephrectomy was performed in 4 patients, all from group B. The other 19 patients were treated conservatively. Complete involution was observed in 8 patients in group A and 6 in group B after a mean follow-up period of 9.2 and 10 months, respectively. Two patients, 1 from each group, later underwent nephrectomy not because of no involution but because of an increase in the size of the kidney involved.Conclusion. Patients with multicystic renal dysplasia have significant associated urologic malformations, and the natural history of the disease is unpredictable. All patients require appropriate investigation of the urinary tract and long-term follow-up.The most outstanding finding of the study is the much higher involution rate of multicystic renal dysplasia and the rate of associated urologic abnormalities than that reported in the literature. Surgery remains an option for the patients in the absence of no involution. Pediatrics 1998;102(6). URL: http://www.pediatrics.org/cgi/content/ full/102/6/e73; multicystic dysplastic kidney, surgery, conservative.ABBREVIATIONS. MCRD, multicystic renal dysplasia; UPJ, ureteropelvic junction; VUR, vesicoureteral reflux; UVJ, ureterovesical junction. M ulticystic renal dysplasia (MCRD) is the most common form of cystic disease of the kidney in childhood.1 The increasingly widespread use of prenatal diagnostic techniques has revealed that MCRD is apparently even more prevalent than had been assumed. 2 The association of hypertension, malignancy, and incomplete involution in MCRD mandate long-term follow-up, and much controversy has surrounded the question of whether nephrectomy is indicated routinely on diagnosis. 3,4 To assess the natural history of this condition and, for purposes of proper management, the associated urinary malformations, we conducted a 19-year retrospective study of all infants with MCRD who had been diagnosed and treated in our tertiary care medical center.
MATERIALS AND METHODSWe reviewed the charts and radiologic records of the 25 patients with MCRD who w...