The Ask-Upmark kidney: a form of ascending pyelonephritis?

The case is presented of a young girl with recurrent urinary tract infection and vesico-ureteric reflux who developed a small scarred kidney and subsequently, hypertension. Pathologically, the renal changes were compatible with those of an Ask-Upmark kidney. The pathogenesis of the Ask-Upmark kidney is discussed. It is postulated that the lesion is not necessarily of congenital origin but may well be related to infection and intrarenal reflux, it is concluded that long-term follow-up of a young patient with a scarred kidney is indicated.