内視鏡からみた平坦・陥凹型早期胃癌の粘膜内浸潤範囲診断

Endoscopic Diagnosis of the Intramucosal Extent of Infiltration in Flat or Depressed Type Early Gastric Cancers

要旨　過去5年間に，当センターで切除された平坦・陥凹型早期胃癌145病巣(外科手術：96病巣，EMR：49病巣)を対象に，対象病巣の口側境界の内視鏡所見を組織型，粘膜内浸潤様式，腫瘍径，境界の部位，背景粘膜と対比検討した．①組織型が中分化型または未分化型，②粘膜内浸潤様式が中間・深層型，③大きさ31mm以上の病巣，④M領域の小彎，U領域の小彎，後壁の病巣，⑤粘膜の萎縮と腸上皮化生のある病巣で境界不明瞭なものが多い傾向にあった．このような病巣に対しては，観察方法に工夫を凝らし，より正確な浸潤範囲診断を行うことによって，縮小手術の根治性を高めることが可能と考えられる．

　We studied endoscopic appearance of the oral border to guage the intramucosal extent of infiltration in 145 cases of flat or depressed type early gastric cancers. Endoscopically, we divided them into four groups, viz. clear type, relatively clear type, relatively unclear type and unclear type. The characteristics of relatively unclear type and unclear type are follows:

　1) histologically, moderately differentiated or undifferentiated type, 　2) their intramucosal infiltration pattern is the intermediate or deep type, 　3) their tumor size is more than 31 mm, 　4) they are located in the lesser curvature of the U and M region, or in the posterior wall of the U region, 　5) their back-ground mucosa is accompanied with atrophy of the proper gastric gland or intestinal metaplasia.

　In conclusion, it can be said that we should diagnose these lesions with careful observation, clipping and biopsy.