前立腺粘液腺癌の1例

Abstract

64歳男.排尿困難から尿閉となり近医を受診した.入院してバルンを留置し, 精査加療目的で著者の病院に転院した.触診上前立腺に悪性を疑う所見はなく, PSAも正常であった為尿道狭窄及び軽度の前立腺肥大症を考えた.尿道造影上尿道の壁不整が見られ, PSAが上昇しない前立腺の腫瘍又は尿道腫瘍も否定できない為, チーマンカテーテルによる経尿道前立腺切除術を施行した.切除標本の病理診断はmucinous adenocarcinomaであった.尿道, 膀胱頸部まで癌の浸潤が認められた為, テガフールウラシルの経口投与を開始した.膀胱前立腺全摘・尿管皮膚瘻造設術を施行した.術後リンパ瘻が生じたがそれ以外は合併症もなく経過は順調で退院した.術後17.5ヵ月を経過しているが, 再発なく元気に生活している

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).