Anterior Urethral Metastasis of Prostate Cancer Presenting With Minimal Prostate-Specific Antigen (PSA) Elevation

Prostate cancer metastasising to the urethra is a very rare occurrence of advanced disease. Herein, we present a case of a 64-year-old male patient presenting with urethral metastasis of prostate adenocarcinoma. This patient initially presented in May 2024 with visible haematuria, with flexible cystoscopy in July 2024 revealing a polypoid lesion in the anterior urethra measuring 1.5 cm and a second villous growth in the prostatic fossa. The patient's initial prostate adenocarcinoma was diagnosed in 2017, managed with transurethral resection of the prostate (TURP), radical radiotherapy, and adjuvant hormonal therapy up until 2019, with stable disease and prostate-specific antigen (PSA) until 2024. Initial management was resection of both lesions with subsequent repeat cystoscopy for further clearance of the anterior urethral lesion. Histopathological analysis of both lesions revealed the lesion in the prostatic fossa to be a nephrogenic metaplasia and the anterior urethral lesion to be prostatic adenocarcinoma (Gleason 4+4). After a multidisciplinary team discussion, the patient was deemed for further hormonal treatment to manage this new metastatic deposit. Continued oncological review and management are still underway. Occult metastasis of prostate cancer in this manner is extremely rare in the literature and requires early detection and clinical vigilance for timely treatment.