中心陥凹部の深達度判定に迷ったⅡa＋Ⅱc型早期胃癌の1症例

Early Gastric Cancer, Type Ⅱa+Ⅱc, Perplexing in Estimation of Depth Invasion at the Central Depressed Portion. Report of a Case

　今回，われわれはこれまでに経験した早期胃癌症例を洗い直してみた．そして，深達度診断上Ⅱa＋Ⅱc型早期胃癌で，中心陥凹部の深達度をmかsmか苦慮し，最終的にはsmと術前診断したm癌を取り上げた．若干の検討を加えて報告する．

　A 54-year-old woman visited our hospital because of transient nausea and epigastric discomfort. Endoscopic study showed a round, slightly elevated lesion on the posterior wall of the antrum. The lesion proved to be well differentiated adenocarcinoma by the biopsy specimens. X-ray investigation revealed a well demarcated oval Ⅱa+Ⅱc type early gastric cancer 20×25 mm in diameter and with 4×4 mm shallow central depression. Peripheral elevation was composed of small nodules, indicating that the invasion reached as far as the proper mucosal layer at this portion. On the other hand, barium was not effaced even by strong compression at central depression during fluoroscopy. Therefore, we thought that the tumor spread into the submucosa at the central depression, though endoscopy showed no discoloration such as redness or white coat.

　Resected specimen proved that invasion was limited to the mucosal layer. We have learned through this case that: 1. Estimation of depth invasion in Ⅱa+Ⅱc type mainly depends on the findings of the peripheral elevation. 2. Central depressed area gives few information about depth invasion, except white coat, a sign of deeper invasion. But further analytical study of central depression should be attempted, because a few exceptions to the rule exist.