術後27年で発症した乳癌の大腸転移の1例

Metastatic Colon Carcinoma 27 Years after Surgery for Breast Cancer, Report of a Case

要旨　症例は67歳の女性で40歳時に右乳癌の手術歴がある．検診で便潜血反応陽性を指摘され注腸検査を施行したところS状結腸と下行結腸に片側性の壁変形像を認めた．大腸内視鏡検査ではS状結腸，下行結腸ともに発赤したなだらかな膨隆を認め，粘膜表面は顆粒状を呈していた．生検ではどちらの部位からも腺癌が検出された．全身検索にて他に異常を認めず左半結腸切除を施行した．病理組織学的に粘膜下層から漿膜まで全層性に増生する低分化型腺癌がみられ一部は粘膜表面まで浸潤しており転移性大腸癌の所見であった．漿膜面にも癌細胞が散在しており癌性腹膜炎を併発した転移性大腸癌であり，乳癌の転移と診断した．乳癌の消化管転移例は少なく術後25年以上経過した例は極めてまれであると考えられる．

　A 67-year-old woman visited a near-by clinic, because her stool was positive for occult blood at a medical check up. She was hospitalized for detailed examination. Barium enema exhibited lateral deformities in the sigmoid and descending colon. Colonoscopy demonstrated red elevated lesions in the sigmoid and descending colon. Biopsies of each lesion showed Group 5, adenocarcinoma. The patient had received right mastectomy 27 years before, but we could not differentiate primary carcinoma and metastatic carcinoma. We carried out left hemicolectomy. Tumor cells permeated diffusely from the submucosal layer to the serosa. Some of the tumor cells had infiltrated the mucosal layer. Histopathological diagnosis was metastatic adenocarcinoma, suggesting metastasis from her original breast cancer. It is rare that colonic metastases occur from breast cancer operated on as long as 27 years before.

　1) Department of Gastroenterology, Social Health Insurance Medical Center, Tokyo