前立腺癌に合併した前立腺囊胞

A case of prostatic cancer with cystic formation

　症例は71歳，男性。1998年に他院にて前立腺低分化型腺癌T3N0M1の診断で内分泌治療を開始した。1999年からは当院で同治療を継続し，2002年8月のCT検査で前立腺背面に1cm大の囊胞性腫瘤を認めた。2005年5月頃から排尿障害と頻尿を訴え，MRI検査で前立腺背側に接する壁在結節を伴う囊胞性腫瘤が10cm大まで増大していた。同年6月に囊胞穿刺吸引術を行い，前立腺癌に合併した前立腺囊胞と診断した。前立腺癌治療中に囊胞形成を認めた症例は本邦2例目である。

　A 71-year-old man who had received endocrine therapy for prostatic carcinoma（T3N0M1）was admitted to Metropolitan Hiroo Hospital complaining of difficulty on voiding. Pelvic CT scan and MRI demonstrated a multiple cystic mass posterior to the prostate gland. Transperineal needle aspiration of the cysts produced bloody fluid of 130ml. The PSA level of the fluid was 2,115.9ng/ml and the sperm was not seen and cytology was negative（class Ⅱ）. Therefore, we thought that it was very likely that the cysts origin was the prostate. 73 cases of prostatic cancer with cystic formation in the Japanese literature were reviewed.