Ask-Upmark kidney with bilateral pelvi-ureteric junction obstruction – A rare entity

Renal segmental hypoplasia (Ask-Upmark kidney) is a congenital disorder, first described by Eric Ask-Upmark in 1929. Habib et al. called it “segmental hypoplasia of the kidney in 1965. Ask Upmark kidney is more in females and present with hypertension or sometimes as recurrent urinary tract infections. Usually unilateral, bilaterally asymmetrical segmental hypoplasia has also been reported. The pathogenesis of Ask-Upmark kidney is controversial, attributing to vesicoureteral reflux (VUR) with intrarenal reflux or possibility of localized developmental arrest. We report a case of two years’ male child presenting as abdominal swelling with respiratory distress. On evaluation he was found to have bilateral pelvi-ureteric junction obstruction and left non-functioning kidney for which he underwent right pyeloplasty and left nephrectomy later on. Histopathology report of left kidney suggestive of segmental renal hypoplasia (Ask-Upmark kidney).