囊胞形成をきたした前立腺癌

Prostate cancer with cystic formation：A case report

65歳，男性。主訴は排便障害。直腸指診で，直腸腹側に手拳大，弾性軟の腫瘤を触知した。CT，MRIにて，前立腺に連続して約8cm大の一部壁不整な囊胞状病変を認め，膀胱と直腸を圧排していた。さらに左内腸骨動静脈領域に同様に内部が囊胞状を呈するリンパ節腫脹を認めた。血清PSA値が高かったため，前立腺癌を疑い，経直腸的生検を行ったが，悪性所見は得られなかった。そこで，腫脹リンパ節の摘出術を施行した。その内容液のPSA値は異常に高く，迅速病理学的検査で前立腺癌と診断された。LH-RHアナログによるホルモン療法を開始し，5か月後の現在，血清PSA値は著減し，前立腺の縮小および自覚症状の改善を認めている。

We treated a prostate cancer with cystic formation in a 65-year-old Japanese man presenting with con-stipation. Fist-sized elastic soft mass was palpable by digital rectal examination. CT and MRI demonstrated a retrovesical cystic mass arisen from the prostate and a cystic swelled lymph node situated between left intra-iliac vein and artery. Serum PSA was elevated to 64.42ng/ml. Because transrectal prostate needle biopsy specimens showed no malignancy,open extirpation of the swollen lymph node was performed. The cyst fluid was bloody with extremely high level of PSA（over 5,100ng/ml）and the pathological examination of the lymph node revealed adenocarcinoma arisen from the prostate. Endocrine therapy with LH-RH analog induced a significant improvement of serum PSA,as well as his symptoms and the expansion of the cyst has not been shown.