Reflux nephropathy in a patient with crossed renal ectopia with fusion

Crossed renal ectopia with fusion is a rare congenital anomaly of the urinary tract. While vesicoureteral reflux has been noted frequently, reflux nephropathy has rarely been reported with this anomaly. I describe here a case of reflux nephropathy in a patient with crossed renal ectopia with fusion. A 14-year-old boy was referred to our hospital for further examination of proteinuria, detected by the school's annual urinary screening program. Laboratory study revealed proteinuria and renal insufficiency. Abdominal computed tomography and voiding cystography disclosed crossed renal ectopia with fusion and vesicoureteral reflux in each moiety. Renal biopsy of the orthotopic kidney showed diffuse interstitial fibrosis and mononuclear cell infiltration, periglomerular fibrosis, glomerular hypertrophy, and focal and global glomerulosclerosis, which were compatible with reflux nephropathy. A low-protein diet and an administration of angiotensin converting enzyme inhibitor decreased the urinary excretion of protein.