Benign inverted papilloma at bladder neck causing acute urinary retention

Abstract

Inverted papilloma of the urinary tract is a rare benign lesion. A 59-year-old male who presented with the chief complaint of gross hematuria and acute urinary retention is described. Cystoscopy revealed a solitary, papillary tumor at the bladder neck. Transurethral resection was performed, and histological examination revealed a pathological diagnosis of inverted papilloma. Following resection, the patient was able to void without difficulty. This is an interesting case of acute urinary retention secondary to an inverted papilloma at the bladder neck causing intermittent outlet obstruction, and we review the literature on inverted papilloma of the bladder.

Figure 1:

(A) Low magnification showing circumscribed inverted growth pattern with anastomosing nests and trabeculae of urothelial cells just beneath and connected to the smooth surface of benign urothelium (10×). (B) Medium magnification showing occasional microcysts in the inverted urothelial nests (25×). (C) High magnification showing occasional focus of mild epithelial atypia with a degenerative appearance of the nuclei (40×).