Abstract

An in situ DNA hybridisation method was used to detect human papillomavirus (HPV) DNA (HPV types 6, 11, 16, and 18), and an immunoperoxidase (IP-PAP) method to detect HPV structural protein expression in paraffin sections of biopsy specimens from 133 men treated for penile (in 114 cases) and anal (in 19 cases) warts. The anatomical distribution on the penis of classic condyloma acuminatum and of papular and flat condylomata was practically identical. The gross appearance of the warts did not correlate with their morphology on light microscopy. The detection rate of dysplasia was very different in the three types of lesions (25% in flat, 50% in acuminatum, and 75% in papular warts). Of 133 lesions, 59 (44.4%) contained HPV antigens, their expression being inversely related to the grade of dysplasia; only 17% of HPV 16 lesions had detectable HPV antigen compared with 50% to 67% in lesions of the other three HPV types. HPV 16 and HPV 18 DNA were most commonly (11%) detectable in Bowenoid lesions; however, most of the HPV 16 and 18 positive cases were found among the flat and acuminatum type of lesions. Though the overall detection rate of HPV DNA (76%) did not correlate with the grade of dysplasia, a clear cut association of HPV 16 and HPV 18 with dysplastic lesions was found, none of the HPV 16 and 25% of the HPV 18 positive cases being devoid of concomitant dysplasia. The corresponding figures for HPV 6 and HPV 11 were 59.2% and 68.8%, respectively. The implications of these findings are discussed in terms of epidemiologically established connections between penile and cervical cancer, with special emphasis of the high risk HPV types 16 and 18. The applicability of in situ DNA hybridisation as a powerful tool in the analysis of specific HPV DNA sequences in routinely processed biopsy specimens from these lesions is emphasised.