Renal Papillary Necrosis Appearing as Bladder Cancer on Imaging

Abstract

A 79-year-old woman with a history of diabetes mellitus and recurrent urinary tract infections (UTIs) presented with acute onset left lower quadrant pain, left-sided back pain, vomiting, and dysuria. Abdominopelvic CT scan revealed left hydroureteronephrosis to the level of the left ureterovesical junction (UVJ) where a bladder mass appeared to be obstructing the left ureteral orifice. The obstruction was ultimately found to be the result of a sloughed renal papilla lodged in the distal ureter, which created an inflammatory mass at the UVJ. Her history of diabetes and frequent UTIs likely predisposed her to the development of renal papillary necrosis (RPN) that resulted in sloughing of a renal papilla, distal ureteral obstruction with subsequent bladder inflammation that mimicked a bladder mass on imaging. RPN is a condition associated with many etiologies and likely represents a common final pathway of several diseases. Although several hypotheses exist, it is primarily thought to be ischemic in nature and is related to the underlying physiology of the renal papillae. We present a case of hydroureteronephrosis and bladder mass secondary to a sloughed renal papilla from RPN.

FIG. 1.

Abdominal and pelvic CT scan revealing left-sided hydroureteronephrosis and delayed nephrogram, suggesting obstruction (A) and bladder mass (B) appearing to obstruct the left ureteral orifice.

FIG. 2.

Final pathology analysis showing (A) duct-like structures filled with inflammatory and microbial cells (blue arrow) and microbial overgrowth (red arrow). (B) Sample of ureteral orifice showing diffuse inflammation with necrotic change and focal microabscesses.