Bladder Squamous Cell Papilloma
Exophytic core lined by cytologically benign squamous epithelium
Uncommon finding, less than 1% of the papillary tumor of the bladder
It affects most commonly elderly patients (mean age of 65 years old).
It affects females slightly more than males.
Bladder. Presentation symptoms include stress incontinence and gross hematuria (Guo et al. 2006).
Surgical resection of the papillary lesion
It is a benign tumor and rarely recurs. Squamous papilloma has been found associated with urothelial neoplasms of the bladder in a low proportion of cases and seems to add a very low risk factor for bladder cancer (Cheng et al. 2000; Guo et al. 2006).
The squamous papilloma is not associated with human papilloma virus infection (HPV), has no p53 nuclear accumulation, and is diploid (Cheng et al. 2000).
Epidermal growth factor receptor [EGFR] expression by immunohistochemistry was described in four of four squamous papilloma lesions tested (Guo et al. 2006).
Squamous papilloma must be differentiated from condyloma acuminatum and verrucous carcinoma (Cheng et al. 2000). Condyloma, unlike squamous papilloma, is HPV-related. Verrucous carcinoma is characterized by bland cytology without koilocytic changes, verrucoid architecture, and large masses without stromal invasion.