An Aspergilloma Mistaken for a Pelviureteral Stone on Nonenhanced CT: A Fungal Bezoar Causing Ureteral Obstruction

Fungus balls rarely cause upper urinary tract obstruction, and they are most often found in patients with diabetes mellitus or impaired immunity. The computed tomography (CT) findings of fungal bezoars of the urinary tract are nonspecific and have rarely been described, while in most cases, radiolucent filling defects are observed on excretory or retrograde urography. Here, an unusual case of an aspergilloma causing ureteral obstruction is presented; it was initially mistaken for a pelviureteral stone on nonenhanced CT.