Penile verrucous carcinoma: a clinicopathologic, human papillomavirus typing and flow cytometric analysis

The relationship of various verruciform squamous cell proliferations of the penis such as verrucous carcinoma, with or without anaplasia and giant condyloma, is uncertain. We conducted clinicopathologic, flow cytometric, and HPV typing studies on 15 cases of penile verrucous carcinoma to investigate its place in the spectrum of genital squamous proliferations. The results show a high degree of morphologic uniformity with respect to Ackerman's original diagnostic criteria, as well as to several other histopathologic features evaluated. The latter include polygonal squamous cells with glassy cytoplasm, centrally located vesicular nuclei, intercellular edema, well-formed cellular bridges, and absence or paucity of koilocytes, true fibrovascular cores, and keratohyalin granules. Intraepithelial abscesses and crust-formation were present in many cases. Four cases contained microscopic foci of cellular anaplasia. These hybrid verrucous-squamous carcinomas presented and behaved similarly to the pure verrucous carcinomas. Tumor recurrence was correlated with extent of initial surgical management. DNA ploidy analysis by flow cytometry performed on eight pure and two hybrid tumors showed uniform diploid populations with similar G1/G2 fractions in both groups. Eight pure and two hybrid tumors evaluated for HPV by isotopic in situ hybridization were uniformly negative for HPV types 6, 11, 16, 18, and 31. The results show that penile verrucous carcinoma demonstrates characteristic and uniform morphologic features and does not contain the HPV types typically associated with condyloma acuminatum, giant condyloma of Buschke-Löwenstein, and condylomatous carcinoma.