Zoon's balanitis.

Superficial lesions of the glans penis can cause diagnostic difficulties. Zoon's balanitis can be distinguished by characteristic histological changes affecting the epidermis and the dermal vasculature. A 44-year-old male presented after having blood-staining of his underclothes for 5 months. Upon examination, the glans showed a red, moist plaque. Circumcision was performed, and the biopsy showed plasma cell balanitis. Following circumcision, the lesion healed completely.