[Inverted papilloma of the bladder with mild atypia]

A case of inverted papilloma of the bladder with mild atypia in a 31-year-old male is reported. The patient was admitted complaining of macroscopic hematuria. An excretory urogram revealed a small filling defect in the center of the bladder. A 15 x 11 mm. exophytic lesion was noted at the center of the trigone by cystoscopy and ultrasonography. The patient underwent transurethral resection of the bladder tumor and selected-site mucosal biopsies. The result of a histopathological examination of the tumor was an inverted configuration with nuclear atypia, corresponding to transitional cell carcinoma, grade 1. No histopathological abnormalities in the normal-appearing bladder mucosa were observed. The patient has been subsequently followed up for 43 months and there was no evidence of recurrence.