Ectopic prostatic tissue with eosinophilic epithelial metaplasia in anterior urethra: A case report

To date, reported cases of ectopic prostatic tissue occurring in the genitourinary tract, particularly in the anterior urethra, are exceedingly rare. We report a case of a 20-year-old man who is presented with cystic lesion on the anterior (penile) urethra. Routine investigation shows a micro-cystic submucous mass, near to the external orifice of the urethra. The performed surgical excision and histological investigation confirm that the lesion is a prostatic tissue ectopy. Histologically and immunohistochemically, the cyst wall is lined with prostatic-type benign epithelium. In addition, interspersed foci of eosinophilic metaplasia (EM) are found among the prostatic epithelium. The subsequent targeted histochemical, immunohistochemical, and ultrastructural study confirm the presence of EM in the ectopic prostatic tissue. This is the first case that presents EM occurring in ectopic prostatic tissue. The presence of EM can be used as an additional argument supporting the prostatic origin and the benign character of the lesion. The histogenesis of the ectopic prostatic tissue in the urethra is discussed. We suggest that it is most likely a hyperplastic epithelial response of embryonic prostatic nests in the urethra.