食道ESD瘢痕部癌の病理組織学的特徴

Histopathological Characteristics of Esophageal Endoscopic Submucosal Dissection Scar

要旨●食道ESDによって生じた線維化領域を粘膜筋板の有無にかかわらず“ESD瘢痕”と定義し，同部に扁平上皮癌が存在した4例を“ESD瘢痕部癌”として検討した．4例はいずれも領域性が明らかな癌で，粘膜固有層に浸潤し，脈管侵襲は認めなかった．表層分化傾向を有し主に基底側で細胞異型が強い表層分化型癌が2例で，他の2例にも同様の成分が認められた．錯角化は4例にみられ，うち2例はヨード不染領域よりも病変の範囲が広かった．p53の過剰発現は2例に認め，腫瘍の同定に有用であった．ESD瘢痕部癌の病理組織学的特徴を明らかにするためには，ESD瘢痕およびESD瘢痕部癌の定義を明確にしつつ，症例を集積する必要がある．

　An ESD（endoscopic submucosal dissection）scar is an area of subepithelial fibrosis caused by esophageal ESD, with or without muscularis mucosae. Four patients with squamous cell carcinoma in the esophageal ESD scar were examined as ESD scar carcinoma. All carcinomas were of clear regional characteristics, invading the lamina propria but not the vascular vessels. Two cases were superficially differentiated carcinomas with a tendency toward superficial differentiation and marked cellular atypia mainly on the basal cell layer, and the other two cases had similar components. Hyperparakeratosis was also seen in all cases, and two of them had more extensive lesions than the area that failed to retain Lugol-iodine. Overexpression of p53 was observed in two cases and was useful for tumor identification. Accumulating cases while defining ESD scars and ESD scar carcinoma is necessary to clarify the histopathological characteristics of ESD scar carcinoma.