[Solitary ulcer of unknown etiology on the glans penis].

Ulcerations of the prepuce or foreskin of the penis are rare in the day-to-day life of a urologist. The most common differential diagnosis is invasive penile cancer, which is why other diagnoses are often overshadowed. We report a case of a syphilitic lesion which was initially misdiagnosed as penile cancer. Considering the rising incidence of syphilis worldwide, syphilis should be considered as a possible cause of any solitary penile ulcer.