Squamous papilloma of the urinary tract is unrelated to condyloma acuminata

BACKGROUND. To the authors' knowledge, there is no previous report of squam ous papilloma of the urinary tract. It is uncertain whether there is a corr elation between squamous papilloma, condyloma acuminatum, and verrucous car cinoma. METHODS. The authors evaluated the clinical and pathologic features of squa mous papilloma (5 of the bladder, 2 of the urethra), condyloma acuminatum ( 3 cases), and verrucous carcinoma (3 cases) of the urinary bladder and perf ormed human papillomavirus (HPV) DNA in situ hybridization studies to deter mine whether HPV was a common feature shared by these lesions. In addition, DNA ploidy evaluation by image cytometry and p53 immunohistochemical stain ing were performed. RESULTS. Squamous papilloma of the urinary tract occurred in elderly women and followed a benign clinical course with infrequent recurrence. All squam ous papillomas were HPV DNA negative and DNA diploid with no or minimal p53 nuclear accumulation. Condyloma acuminata of the bladder contained HPV DNA , increased p53 protein expression, and aneuploid DNA content. All three ca ses of condyloma acuminata were associated with coexistent condylomata of t he external genitalia, and two required pelvic exenteration for uncontrolle d expansile growth. Verrucous carcinoma of the bladder occurred in elderly patients. All three cases of verrucous carcinoma were negative for HPV DNA and DNA aneuploid, and they exhibited consistent p53 expression. CONCLUSIONS. These data indicate that squamous papilloma is a distinct enti ty not related to condyloma or verrucous carcinoma. These lesions are benig n, HPV DNA negative, DNA diploid, and they lack p53 overaccumulation. (C) 2 000 American Cancer Society.