囊胞形成を伴う前立腺癌

A case of cystic prostate cancer with urinary retention treated by transrectal needle aspiration of the cyst

　76歳，男性。尿閉を主訴に来院した。触診，PSA，腹部CTから，囊胞形成を伴う前立腺癌を疑った。確定診断のため経直腸的前立腺針生検を施行し，併せて囊胞穿刺を行った。病理は中分化型腺癌で，穿刺により得られた囊胞内容液は血性，526mlであった。穿刺後自己排尿が可能になった。臨床病期T4N0 M0の診断にてホルモン療法を開始した。PSA，腫瘍容積はそれぞれ著明に低下，縮小した。現在外来通院中である。

A 76-year-old Japanese man presented with a complaint of urinary retention. On digital rectal examination,a cystic prostate with a hard elastic mass was palpated. The serum concentration of prostate specific antigen（PSA）was elevated to 1,585ng/ml. Multidetector-row helical computed tomography revealed a huge cystic tumor with solid lesion occupying the pelvic cavity. Transrectal needle biopsy demonstrated moderately differentiated adenocarcinoma of the prostate and simultaneous aspiration of the cyst yielded old-bloody fluid of 526ml,which brought a significant improvement of urination. With a clinical diagnosis of prostate cancer（T4N0 M0）with cyst formation,anti-androgen therapy with a luteinizing hormone relaeasing hormone analogue and flutamide significantly lowered the serum PSA to normal level and the tumor was reduced in volume. This is the 70th case of prostate cancer with cyst formation reported in Japan.