脳，皮膚および縦隔に転移した直腸sm内分泌細胞癌の1例

Submucosal Invasive Endocrine Cell Carcinoma of the Rectum with Metastasis to the Brain, Skin and Mediastinum, Report of a Case

要旨　患者は63歳，男性．下血と脱肛を主訴に当科初診．大腸内視鏡検査で，直腸のIsp型腫瘍をポリペクトミーされた．病理組織学的には壁深達度smの多数のGrimelius陽性細胞を認める内分泌細胞癌であった．その後，根治手術として低位前方切除術(D₃)およびJ型結腸囊肛門吻合術が施行された．組織学的にn₂(+)であったが残存腫瘍は認められなかった．術後2年2か月後，脳，皮膚および縦隔に転移を来し死亡した．本稿では，直腸内分泌細胞癌が深達度smにもかかわらず，早期に転移し予後不良な高度悪性腫瘍であることを報告するとともに，内分泌細胞癌を免疫組織化学的，電顕学的および分子生物学的に検討し考察を加えた．

　A 63-year-old man was admitted to our hospital with complaints of bloody stool and anal prolapse. Colonofiberscopic examination revealed a subpedunculated tumor in the lower rectum which was removed endoscopically. Histologically, the removed tumor showed an endocrine cell carcinoma with massive submucosal invasion, the cut margin of which was suspected of having been invaded by the cancer. A colonic J shaped pouch-anal anastomosis following low anterior resection with dissection of D₃ lymph nodes was carried out. Histologically, the resected specimen showed no residual cancer in the rectum, but there were cancer metastases to several regional lymph nodes. Two years and two months after the operation, the patient died of metastatic endocrine cell carcinoma to the brain, skin and mediastinum. A clinical case of endocrine cell carcinoma with poor prognosis was reported. In addition, immunohistochemical and molecular biological characteristics of the tumor are discussed in this paper.