Anuria due to bilateral ureteral obstruction by Aspergillus flavus in an adult male.

Mycelial clumps or bezoars (fungus balls) as a cause of upper urinary tract obstruction are rare, with fewer than 60 cases previously reported. Anuria due to bilateral ureteral obstruction with mycelial clumps is most rare. We report a man with bilateral ureteral obstruction by Aspergillus flavus and describe his diagnosis and treatment. It is remarkable that imaging modalities, including excretory urography, computed tomography, and retrograde ureteropyelography, did not identify filling defects to suggest a fungal causation of the ureteral obstruction, even in the presence of a rapidly progressing process. For this reason, one should consider a fungal infestation in high-risk patients with obstructive uropathy of unknown etiology.