Verrucous Squamous Hyperplasia of the Urinary Bladder: A Series of 23 Cases

Context.—There is scant literature describing verrucous squamous hyperplasia of the urinary bladder. Objective.—To investigate the possible association between verrucous squamous hyperplasia and carcinoma. Design.—The case files of the senior author were searched for cases of verrucous squamous hyperplasia diagnosed between August 2010 and February 2021. Cases with available material were tested for in situ hybridization with human papillomavirus, and cases with available material unassociated with carcinoma underwent immunohistochemistry for p53. Results.—We gathered a series of 23 cases, the largest to date. Eleven cases were associated with carcinoma at diagnosis. Of the 7 cases unassociated with carcinoma in which follow-up was available, 1 patient (14.3%) was given a clinical diagnosis of carcinoma with recommended cystectomy, 2 (28.6%) had benign diagnoses, and 4 (57.1%) were dead not from disease. Of the 13 cases with available material, 13 (100%) were negative for human papillomavirus by high-risk in situ hybridization. Conclusions.—Based on the small number of cases with limited follow-up, it is unclear whether verrucous squamous hyperplasia represents a precursor lesion or simply a high-risk association. Until more evidence is accumulated, patients with verrucous squamous hyperplasia of the urinary bladder should receive close clinical follow-up.