Association of congenital megacalycosis and ipsilateral segmental megaureter

Four cases of congenital megacalycosis associated with ipsilateral segmental megaureter in children are presented. This association has not been emphasized, although review of the English and French literature revealed eight such cases. In all cases, the concurrent entities are unilateral, with a left-sided predominance and a male prevalence. The diagnosis of megacalycosis is presumed in four of the cases by normal function and prompt emptying of the calyceal systems on diuretic renography and/or urography. The presence of normal caliber renal pelvis interposed between the dilated collecting system and the distal dilated ureter without evidence of vesicoureteral reflux implies the coexistence of ipsilateral idiopathic megaureter. The patients usually present because of urinary tract infection and/or calculus formation, but respond well to conservative therapy.