上皮内伸展を伴い粘膜下腫瘍様の形態を呈した食道低分化型扁平上皮癌の1例

Esophageal Cancer Resembling a Submucosal Tumor with Intraepithelial Spread, Report of a Case

要旨　患者は78歳，女性．約1か月前からの食事のつかえ感を主訴に近医受診し，食道腫瘍を指摘されて当院紹介となった．上部消化管造影および内視鏡検査所見では胸部中部食道に径5cmの粘膜下腫瘍様隆起を認め，さらに内視鏡所見でその周囲に上皮内伸展を思わせるヨード不染帯を認めた．生検にて低分化型扁平上皮癌と診断し，右開胸開腹食道亜全摘術を施行した．病理診断では，低分化型扁平上皮癌で深達度sm₃，脈管侵襲陽性で，1，2群リンパ節への転移を認めた．切除標本上も中央の隆起部分は完全に非腫瘍性上皮に覆われているものの，周囲の上皮内伸展部は通常の上皮内癌の形態をとっており，比較的まれな形態と考えられた．

　The patient was a 78-year-old woman who was found to have an esophageal tumor, because of increasing dysphasia about one month ago. Esophagography and endoscopy demonstrated an elevated lesion, measuring as much as 5 cm in size, like a submucosal tumor in the middle thoracic esophagus. Endoscopic examination revealed intraepithelial spread around the elevated lesion. Pathological findings of the biopsied specimen were suggestive of poorly differentiated squamous cell carcinoma. Total esophagectomy was performed. Histopathological findings showed poorly differentiated squamous cell carcinoma, which had invaded as deep as the sm₃, with vascular invasion and lymph node metastasis. Gross appearance of the resected specimen showed a submucosal tumor-like elevation, which was completely covered with non-neoplastic epithelium and surrounded by the intraepithelial spread. It was considered that its gross appearance was comparatively rare as a squamous cell carcinoma of the esophagus.