[Mucinous adenocarcinoma of the prostate: a case report].

A 64-year-old man presented to our department with urinary retention. Rectal examination revealed a small and soft prostate. PSA was within the normal limits. Computed tomography showed a low-density area around the prostatic urethra and urethrography revealed an irregular prostatic urethra compressed by the prostate. We performed transurethral resection of prostate (TUR-P). On resectoscopy, jelly-like round substances were seen in the bladder. Prostatic urethra and bladder neck were covered with a jelly-like substance. Pathological diagnosis was mucinous adenocarcinoma of the prostate with bladder neck involvement. One month later after TUR-P, we performed radical cystoprostatectomy. Histological findings showed the cancer, of which 70-80% was composed of extracellular mucin lakes containing floating clumps of tumor cells. Mucin lake was stained with alcian blue and PAS. Immunohistochemical study revealed the tumor cells positive for carcinoembryonic antigen (CEA) and negative for prostatic specific antigen (PSA).