Rare Cause of Hydronephrosis

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. FIG. 1. Abdominopelvic computed tomographic scan showed a cystic mass involving the right kidney. A 55-year-old female presented with right flank pain that had developed 7 days previously and was diagnosed as having right hydronephrosis on an abdominopelvic computed tomographic (CT) scan at a local clinic. She was referred to the Asan Medical Center for further evaluation. At the time of the initial visit to the Asan Medical Center, the patient's right flank pain had subsided and the physical examination revealed no significant findings. The results of blood examinations were as follows (normal range in parentheses): peripheral white cell count, 6,400/μL (4,000 to 10,000); C-reactive protein, 1.03 mg/dL (＜0.6); creatinine, 0.96 mg/dL (0.70 to 1.40); alanine aminotransferase, 13 IU/L (＜40); aspartate aminotransferase, 15 IU/L (＜40). Proteinuria was not observed, and urinary sedimentation included 6 to 10 white blood cells/high-power field. Urine culture and acid fast bacillus stain/culture showed no microorganisms. An outside abdominopelvic CT scan revealed a con-glomerated cystic mass involving the upper portion of the right kidney suggesting hydronephrosis, and perfusion of the right kidney was less than that of the left kidney (Fig. 1). A 99m technetium-mercaptoacetyltriglycine (99m Tc-MAG3) renal scan revealed a severe decrease in right kidney function (relative function 16.1%) and complete obstruction of the right urinary tract (T1/2＞20 minutes). Even after Lasix injection, cortical transit, parenchymal washout, and ex-cretion of the right kidney were not visible.