Ectopic ureterocele with pyonephrosis: a potential mimic of acute pyelonephritis on renal cortical scintigraphy.

Demonstration of cortical defects by renal cortical scintigraphy provides supportive evidence of acute pyelonephritis or renal scarring in the appropriate clinical settings. The presented case illustrates the potential for a small nonfunctioning or poorly functioning obstructed upper pole of a duplex kidney to mimic a pyelonephritic cortical defect and underscores the importance of the correlation between renal cortical scintigraphy and anatomic imaging studies.