胃のⅡb病変症例―その内視鏡像の特徴と分類の試み

Endoscopic Classification of Type Ⅱb Early Gastric Cancer

　最近，Ⅱbの発見数も次第に増加してきた．そして，その内視鏡所見も乏しいとはいえ，何とかその特徴を捕えるところまできたように思う．そこで，代表的な症例を提示しながら，Ⅱbの内視鏡所見についてのわれわれの考えを述べてみたい．．

　In our Institute, 973 lesions of early gastric cancer have been operated on during 15 years and only 41cases, 46 lesions of them (4.7%) have been Ⅱb type. Fourteen lesions of 46 (30.4%) were diagnosed endoscopically and other 32 lesions (69.6%) were detected on the histopathological examination of the surgical specimens with other diseases.

　The diagnostic process of the endoscopically detected Ⅱb (14 lesions) was analyzed and it was classifled into 3 courses: the first course in which carcinoma was proved in the biopsy specimens obtained from the small reddish area (8 lesions), the second in which carcinoma was proved in the biopsy specimens obtained from the large white area (4 lesions) and the third in which carcinoma was proved unexpectedly in the biopsy specimens obtained from the other lesions (2 lesions). In the third course, the endoscopic findings of Ⅱb were not clear at all. so, gastroscopic findings of Ⅱb may be now considered to consist of 2 types of the mucosal discoloration; they may be called the red type and white type.

　Histopathological examination of two types showed well differentiated type of adenocarcinoma in the red type and poorly differentiated adenocarcinoma including signet ring cell carcinoma in the white type.

This discoloration of the white type of Ⅱb may be caused by the number of the signet ring cell and the invasion of carcinoma cell to the submucosa. In order to diagnose endoscopically more cases of Ⅱb type of early gastric cancer, these two types of the mucosal discoloration must be detected and the biopsy specimen must be obtained accurately from these two lesions.