RESUMO
Penile cysts are rare benign lesions. Their clinical or pathological diagnosis is extremely difficult. Less than 200 cases have been reported in literature. Most of them are asymptomatic and present since birth, but usually they are only detectable in adolescence or adulthood. These lesions rarely interfere with sexual function. These cysts most likely arise from ectopic urethral mucosa sequestered in the penile skin during embryologic development. We report a rare case of a 55-year-old man with a 4.5 × 4 cm nodule on the prepuce (ventral surface), which appeared two years ago and interfered with his sexual function. The nodule was excised by circumcision and a histopathological examination revealed a mucoid cyst of penis with squamous metaplasia. No recurrence was observed at a one year follow-up and the patient's sexual function returned to normal.