Penile cutaneous horn is a clinical term that describes protruding hyperkeratosis, usually conical in shape, located on penile glans. Penile localization of this lesion, predominantly located on sun-exposed areas, is very rare. The association with
malignancy on the penis makes proper identification of these lesions essential. We present a 45-year-old man with a cutaneous horn, 25 mm in size, located on the basis of penile glans. The patient had a history of
phimosis, pseudoepitheliomatous balanoposthitis, surgical excision of penile verrucous
squamous cell carcinoma (SCC) and postoperative
radiotherapy of
carcinoma in situ on the same localization, ten years before. Complete surgical removal of the horn with separate excision of the margins and base was done. Pathologic examination revealed squamous
hyperplasia with suspicion of
carcinoma in situ. Additional negative
p16(INK4a) immunohistochemical analysis confirmed benign proliferative lesion.
DNA polymerase chain reaction for human papilloma virus
infection was negative. These findings suggested sparing
surgical procedure in our patient, without indication for partial penile
amputation, but with mandatory follow-up. Our case confirmed the association of pseudoepitheliomatous balanoposthitis with verrucous SCC, as well as the possible influence of
radiotherapy on the development of penile cutaneous horn. Additionally, we showed the important role
p16(INK4a) immunohistochemical analysis in the differential diagnosis of alterations adjacent to invasive SCC of the penis.