Incidental Detection of Poorly Differentiated Neuroendocrine Carcinoma in Penile Urethra on 18 F-Fluciclovine PET/CT.

We report the case of an 88-year-old man with suspected biochemical recurrence of prostate cancer, in whom 18 F-fluciclovine PET/CT was performed in the context of rising prostate-specific antigen (PSA) levels. Incidental identification of penile urethral activity was observed. A subsequent urethral biopsy revealed a treatment-related, poorly differentiated neuroendocrine carcinoma of prostatic origin, with metastasis to the penile urethra.