膀胱に発生した肉腫様癌(Sarcomatoid carcinoma)の1例

Abstract

症例は78歳男性で, 2ヵ月前の喉頭癌摘出術時に術前の尿道カテーテル留置の際, 肉眼的血尿を認めたため, 術後に紹介来診した.膀胱鏡にて右膀胱頂部に直径約5cmの非乳頭状広基性の腫瘍を認め精査加療目的で入院となった.経尿道的膀胱腫瘍生検の結果, 腫瘍表面は凝血塊に覆われ石灰化が著明で生検組織標本からは腫瘍細胞は得られなかったが, 画像所見から筋層浸潤を強く疑い, 術前診断T3bN0M0として膀胱全摘除術および回腸導管造設術を施行した.摘出標本の病理組織学的所見から肉腫様癌(sarcomatoid carcinoma), grade 3, pT3bpN0と診断された.術後4日目にMRSAによる創部感染に基づく腹膜炎を発症し, 術後5日目に腹膜炎に対する腹腔内洗浄・ドレナージの再手術を施行し, 塩酸バンコマイシンによる化学療法を行った.再手術後の経過は良好で, 術後10ヵ月の現在再発は認めていない

The patient was a 78-year-old man with gross hematuria. A non-papillary and non-pedunculated tumor was found on the posterior wall of the bladder by cystoscopic examination. Total cystectomy with construction of ileal conduit was performed. Histologically, the tumor was composed of carcinomatous and sarcomatous elements. The carcinomatous element was compatible with grade 3 transitional cell carcinoma. The sarcomatous element was composed of osteosarcomatous, chondrosarcomatous pattern and undifferentiated malignant spindle cell component. Immunohistochemical examination demonstrated the presence of keratin, cytokeratin and epithelial membrane antigen in both carcinomatous and sarcomatous elements. Therefore, we diagnosed this tumor as sarcomatoid carcinoma. The patient has remained well without any evidence of recurrence for 10 months after operation.