Barrett上皮内に発生した食道腺癌の1例

Type-Ⅱb Adenocarcinoma in a Short Segment Barrett's Epithelium, Report of a Case

要旨　患者は，78歳男性．検診目的の内視鏡検査で，食道胃接合部に異常を指摘され，精査治療目的に当院入院．内視鏡検査では，食道下端に全周性の発赤するわずかな陥凹性病変があり，前壁～右壁の陥凹内には，微細顆粒状の凹凸を認めた．生検では，well differentiated tubular adenocarcinomaであった．食道造影検査では，Billroth-Ⅱ再建の残胃でsliding herniaを認めた．EG-junctionのほぼ全周に，微細顆粒状の変化があり，後壁には不整形の明らかな陥凹を認めた．病変の長径は15mmであった．長径15mm，ほぼ全周性のBarrett食道腺癌，深達度mの診断で，下部食道切除・残胃全摘・脾摘・食道空腸Roux-Y吻合術を行った．切除標本の病理組織所見では，大きさ15×55mm，Ⅱbであった．腺癌の病巣の下には，二層性の粘膜筋板があり，粘膜下層には固有食道腺がみられ，筋層は食道の構造を示しており，Barrett食道腺癌，深達度m．ly₀，v₀，n₀であった．

　A 78-year-old man was admitted to our hospital because of an abnormality in the lower esophagus. He had been without complaints until an annual endoscopic check-up revealed the esophageal mucosal change. Further endoscopic study identified a short segmented and circumferencial reddening of the mucosa with granular changes in the distal esophagus close to the esophago-gastric junction. An esophagogram revealed a slightly depressed and circumferencial lesion with fine granular changes in the lower esophagus. The axial size of the lesion was 15 mm. Histologic studies on endoscopic bite biopsy specimens revealed well differentiated adenocarcinoma. No atrophic change was identified in cardiac mucosa adjacent to the cancer lesion. Clinical evaluation of the esophageal lesion was type Ⅱb adenocarcinoma confined to the mucosa arising from short segment Barrett's epithelium. Surgical treatment was carried out involving distal esophagectomy with total resection of the residual stomach and splenectomy. Post operative course was uneventful. Histological studies on the resected specimens revealed a type IIb adenocarcinoma in the distal esophagus which was confined to the mucosa. The size of the lesion was 15 × 55 mm. Esophageal glands and the duplicated muscularis mucosae below the cancer lesion and normal esophageal proper muscle layer were also identified, suggesting that the lesion had originated from a short segment Barrett's epithelium. No lymph node metastasis or microvascular invasion was identified.