短期間に0-Ⅱc型から0-Ⅲ型に発育した食道表在癌の2例

Type 0-Ⅱc Superficial Esophageal Cancer Lesions Developing into Type 0-Ⅲ, Report of Two Cases

要旨　比較的短期間に病変の形態が変化した2症例を経験した．〔症例1〕，Ⅱcの診断で他院から紹介された．内視鏡治療前の検査では，再生上皮で覆われた陥凹周囲に数個のⅡc病変を認めた．16日後の粘膜切除施行時には，Ⅱc病変の1個が，周囲に盛り上がりを有する0-Ⅲ型に変化していた．切除標本では大きさ3.5×3mmと小さいが，脈管侵襲陽性のsm1癌であった．〔症例2〕は下咽頭癌の重複例であり，初回内視鏡検査時，多発するⅡc病変を認めた．周囲に円盤状の盛り上がりを有したⅡcは，約9週間後の内視鏡再検時には，陥凹が深く，周囲の盛り上がりも著明となり，0-Ⅲ型に変化していた．2症例とも，単純なⅡcとは異なり，小病変のときから周囲に円盤状の盛り上がりが見られる病変であった．

　Two cases with superficial and slightly depressed type (0-Ⅱc) lesions which developed into superficial and distinctly depressed type lesions (0-Ⅲ) were reported. Each case showed slight depression with minimal marginal elevation at the initial endoscopy. Gross findings by coventional endoscopy were suggestive of superficial and slightly depressed type (0-Ⅱc) lesions remaining within the mucosa. At the same time, endoscopic double staining by toluidine blue and iodine revealed an ill defined unstained bundle on the marginal elevation suggesting subepithelial cancer infiltration. Each case underwent repeated endoscopy at short intervals for further evaluation before treatment. They showed rapid increase in grade of elevation and depression and were finally diagnosed as type 0-Ⅲ lesions with invasion into the muscularis mucosae (m3) and slightly into the submucosa (sm1). Pathological studies on resected specimens verified the clinical diagnoses.

　These facts suggested that some type 0-Ⅲ submucosal cancer lesions originate from type 0-Ⅱc type mucosal cancers, and gross findings of two cases also suggested points for diagnosis of type 0-Ⅲ lesions in their early stage.