Multicystic dysplastic kidney and posterior urethral valve

Introduction: Multicystic dysplastic kidney (MDK) is a rare congenital anomaly of kidney and urinary tract (CAKUT). The disease is characterized with multiple non-communicating cysts without functional renal parenchyma; nowadays the diagnosis is established with prenatal ultrasound screening of the kidneys and urinary tract. The aim of this work is the presentation of rare association of multicystic dysplastic kidney with posterior urethral valves.

Case report: A healthy male newborn baby was referred for nephro-urological work up due to prenatal diagnosis of multicystic kidney which resolved completely before delivery. The first postnatal ultrasound scan revealed normal morphology of the right kidney and the bladder. At the age of two months the parents complained that the baby had poor urinary stream. Voiding urethrocystography revealed posterior urethral valves and the baby underwent successful valve resection.

Discussion and conclusion: We present a rare association of multicystic dysplastic kidney with posterior urethral valves. This association is very rare and was described in few reports. In the series of Mathiot et al. (J Radiol. 2002) among 54 neonates with diagnosed MDK three had posterior urethral valves. Pooled data from 67 studies including 2159 patients in whom VCUG was performed showed association with posterior urethral valves only in 9 cases (0.42%) (Schreuder MF et al, Nephrol Dial Transplant. 2009). Clinician should suspect urethral valves in infants with poor stream even in the case of normal kidney/bladder ultrasound.

Key words: Multicystic dysplastic kidney, posterior urethral valves, resolution, prenatal, ultrasound