非定型的前立腺癌の1例—soft type carcinoma

ATYPICAL CARCINOMA OF THE PROSTATE: A CASE REPORT (SOFT TYPE CARCINOMA)

I．緒　言

　前立腺癌の臨床像に関して直腸診で前立腺が石様硬に触れること，血清酸フォスファターゼ値の上昇が見られること，頻繁に見られる骨転移はX線写真上骨形成性であること，抗男性ホルモン療法が奏効し発育が緩除であること等は衆知の特徴であり，それが大多数の症例に当てはまると考えられている。勿論これらの特徴の幾つかに欠ける症例には我々日常屡々遭遇しているが直腸診で全く柔かい癌があるとすれば熟練した泌尿器科医といえども診断を誤る可能性が強い。しかしsoft type carcinomaはYoung（1926）^1）の記載以来Thompson（1953）^2）Weller（1957）^3）の報告があり本邦でも最近岩佐（1961）^4）が非定型的前立腺癌（髄様癌）として報告している。

　その特徴は直腸診で硬度軟である他血清酸フォスファターゼの上昇の見られぬこと，骨転移像がX線写真上骨融解性であること，抗男性ホルモン治療が効かないこと等で従来の前立腺癌の臨床像の概念を覆えすものである。我々は生存中確定診断を下し得ず剖検によつて始めて前立腺癌（soft type carcinoma）と診断された一例を経験したので茲に報告する。

So called soft type carcinoma of the prostate is extremely rare in this country. As to this atypical carcinoma following characteristics have been described: 1) the prostate is soft in consistency by rectal palpation 2) acid phosphatase in serum remains within normal limits even in cases with bone metastases 3) in the cases with bone metastases x-ray examination reveales osteolytic changes and not osteoblstic 4) antiandrogenic treatments are ineffective 5) they show rapid development and poor prognosis. A CASE REPORT: C. S. 66 year old Japanese male was admitted to the Keio University Hospital, Department of Urology, complaining of fever and E. coli infection in the urinary tracts. He had treatment s for 8 weeks in Department of Internal Medicine as pneumonia. Rectal examination revealed an enlarged prostate with soft consistency. There were no nodular foci suggesting of malignancy. Determination of serum acid phosphatase showed 0.5 to 1.44 unit (Shinowara), while serum alkaline phosphatase elevated 39.5 to 71.0 unit (Shinowara). There were no osteoblastic shadows on x-ray films of bones. By endoscopy a small tumor was found at the bladder neck. Biopsy of the tumor suggested low differentiated carcinoma originated from vesical mucosa. Eight weeks later the patient died showing hemorrhagic tendency, anemia, high fever and joint pain. An autopsy was performed. A low differentiated carcinoma of the prostate with extensive bone metastases was revealed. Clinical findings of this patient were so atypical that the diagnosis was unable to make before the death.