術前診断にて腎癌が疑われたmixed epithelial and stromal tumor

Mixed epithelial and stromal tumor preoperatively diagnosed as a renal cell carcinoma：A case report

　症例は49歳，女性。2007年7月下旬，左下腹部痛にて当院救急外来を受診した。左尿管結石が疑われ，当科を受診した。CTにて左尿管結石と多房性囊胞性左腎腫瘍を認めた。囊胞性腎癌の可能性も否定できないため，2007年9月中旬，左腎摘除術を施行した。病理診断はmixed epithelial and stromal tumor（MEST）であった。2008年3月下旬まで再発を認めていない。

　A 49-year-old woman complaining left lower abdominal pain came to our hospital in July 2007 and was suspected to have a left ureteral stone. Computed Tomography revealed a left ureteral stone and a cystic tumor in her left kidney. We diagnosed the cystic tumor as category Ⅲ tumor under the Bosniak classification. The possibility of cystic renal cell carcinoma could not be denied,therefore a left nephrectomy was performed in September 2007. Histologically,the tumor was mixed epithelial and stromal tumor of the kidney. The patient was free of disease up to her last visit in March 2008.