前立腺小細胞癌の1例

Abstract

79歳男。尿失禁を主訴とした。直腸診で石様硬の所見を認め、検査所見ではPSAは正常範囲内であった。超音波で前立腺体積145cc、辺縁不整の低エコー領域を認め、腹部CTでは膀胱頸部から後部にかけて腫瘍の浸潤を認め、精嚢・直腸への浸潤も疑われた。前立腺生検を行い、低分化腺癌、Gleason score 5+5=10の診断で、精巣摘除術を行った。一時的に退院となったが、血尿、尿閉、下腹部痛、体調不良が出現し再入院となり、入院後も尿閉、膀胱タンポナーデを繰り返し、下腹部疼痛も改善なく、その後、突然心肺停止状態となった。家族の同意が得られず剖検は行えなかった。前立腺生検標本の再検討で、免疫学的組織診断にて小細胞癌の診断に至った。

A 79-year-old man was admitted to our department with a chief complaint of urinary incontinence. The prostate was enlarged (145 cc), although the serum level of prostate specific antigen (PSA) was within the normal range (1.09 ng/ml). Digital rectal examination showed an enlarged, irregular prostate with stony hardness. We performed a prostate biopsy and histological examinations indicated poorly differentiated adenocarcinoma with a Gleason score of 5+5=10. A computed tomographic (CT) scan revealed a prostatic tumor invading the bladder, seminal vesicle and rectum. He was diagnosed with a stage T4N1M0 adenocarcinoma of the prostate. He was started-on hormonal therapy, but died one month from the start of treatment. Histological and immunohistological examinations were repeated; suggesting small cell neuroendocrine carcinoma of the prostate.