内視鏡的食道粘膜切除後に局所再発を来した1例

Local Recurrence of Mucosal Cancer of the Esophagus after Endoscopic Mucosal Resection, Report of a Case

要旨　患者は60歳，男性．6か月前から嚥下時の痛みと熱い食物摂取時に，しみる感じがあった．内視鏡検査を受け，中部食道に0-Ⅱc型病変（扁平上皮癌）を発見され，精査治療目的で当院に入院した．入院時，理学所見に異常なく，AFPとSCC値の軽度上昇を認めた．病変は0-Ⅱc型，長径2.5cm，深達度m2の扁平上皮癌と診断，リンパ節転移，遠隔臓器転移ともに認めず，内視鏡的粘膜切除術（EMR）を行った．病巣は3分割して切除し，臨床的に完全切除と判定し治療を終了した．19か月後に潰瘍瘢痕部に小さい0-Ⅱb型病変を発見し生検で扁平上皮癌（m1）と診断した．再びEMRを施行し，病変を摘出した．第2回EMR後4年経過するが，再発所見はなく健在である．深達度m2までの食道粘膜癌に対するEMR後の局所再発は水平方向の断端陽性によるものであり，切除時の完全切除の判定を正確にすることで回避できることを述べた．

　A 60-year-old man was admitted to our hospital because of mild odynophagia. He had been doing well until six months before when he felt mild odynophagia and retrosternal irritation while taking hot foods. Upper gastrointestinal endoscopic examination revealed an abnormal finding on the mucosa at the middle third of the thoracic esophagus. He was referred to our hospital for further evaluation and treatment. A type 0-Ⅱc (slightly depressed type) mucosal cancer was identified by esophagoscopic examination and esophagogram. The depth of invasion of cancer was estimated as the lamina propria mucosae. An endoscopic mucosal resection (EMR) was carried out with his consent. The unstained area which suggested border of the mucosal cancer was eradicated by three resections. The esophageal ulcer due to EMR had completely healed in three weeks.

　Histological studies revealed that cancer limited within the lamina propria mucosae (m2), but a cancer tissue was found at the margin of the resected specimen. As no unstained area was found in the ulcer scar by the endoscopic iodine stainig technique, he underwent annual checkup for recurrence. Nineteen months later, a small reddening of the mucosa which could be delineated as an unstained area was detected at the margin of the esophageal ulcer scar by the endoscopic iodine staining technique. An bite biopsy from the unstained area revealed squamous cell carcinoma which was confined to the epithelium. The additional EMR removed a small unstained area with neighbouring normal mucosa. Histological examination of the resected specimen verified the clinical estimation. He has been doing well without any sign of recurrence for four years following after the second EMR.