結節性変化の目立ったⅡc型早期胃癌の1例

Ⅱc Type Early Gastric Cancer with Marked Nodularity of the Base, Report of a Case

要旨　Ⅱc陥凹内の結節の部分で，癌のsm浸潤が認められた1例を呈示し，陥凹型早期胃癌の深達度診断における，陥凹内部の所見の重要性について報告した．患者は65歳の女性で，自覚症状なく，胃癌検診にて異常を指摘され来院した．胃X線，内視鏡検査では，胃角部後壁にⅡC型早期胃癌を認めた．Ⅱc陥凹内には，著明な結節性変化を伴っており，再生粘膜あるいは正常粘膜の遺残と診断したが，組織所見では，肛側のやや褪色した結節の部分でⅡc面の約1/2の範囲で粘膜下層への癌浸潤を認めた．本症例は，Ⅱc内の結節性変化が，癌のsm浸潤の重要な所見であることを示唆するものであった．

　We report here 65-year-old female with a lesion of type Ⅱc early gastric cancer, the base of which had nodularity of various sizes. Histological examination revealed adenocarcinoma mucocellulare with infiltration to submucosal layer of a discolored nodule of the floor.

　Generally speaking, differentiation between mucosal and submucosal cancers poses an important problem. In type Ⅱc early gastric cancer, sm invasion is indicated by such signs as drumstick formation, fusion and nodularity of converging folds at the border of depression. When limited to the depressed area of the mucosa, however, sm invasion is indicated only by nodular change and stiffness of the base. On the other hand, mucosal surface irregularities are common in Ⅱc base, especially in undifferentiated adenocarcinoma. Thus, it is necessary to distinguish nodularity due to sm invasion from that due to other causes, such as regenerative mucosa, residual normal mucosa and fibrosis of ulcer scar. The findings obtained to date indicate that it is important to make careful observation for nodularity in Ⅱc base in diagnosing depth of invasion in Ⅱc type early gastric cancer.