PSAが低値を示した摘出重量310gの前立腺肥大症

A case report of giant BPH with low level of serum PSA

　摘出重量が200g以上と定義される巨大前立腺肥大症は比較的稀である。症例は72歳，男性で，主訴は頻尿，排尿時痛であった。巨大な前立腺肥大症が認められ，膀胱結石，慢性膀胱炎を合併し，血清PSA値は0.5ng/mlと低値を示した。恥骨上式前立腺被膜下摘除術を施行し，摘出重量は310gで本邦の報告例中7番目の大きさであった。組織学的には，平滑筋細胞の充実性増殖が主体で，腺構造がまったく欠如し，血清PSAの低値の原因と考えられた。

Giant prostatic hyperplasia,defined as the prostatic volume exceeding 200g is uncommon. A 72-year-old man with severe frequent and painful urination,was diagnosed as giant benign prostatic hyperplasia with bladder stones and chronic cystitis. The serum PSA was 0.5ng/ml. Suprapubic simple prostatectomy was performed and the surgical specimen weighed 310g which ranked as the seventh largest in Japanese urological literature. Histopathological findings were diffuse smooth muscle cell proliferation without prostatic epithelium,resembling leiomyoma,which might be a cause of low serum PSA.（Rinsho Hinyokika 60：409-412,2006）