胃生検により診断しえたⅡb型早期胃癌の2例

Type Ⅱb Early Gastric Cancer Diagnosed by Stomach Biopsy, Report of Two Cases

　近年，X線および内視鏡診断技術の進歩によりⅡb型早期胃癌の報告例が増加してきたが，単独Ⅱbの術前診断は困難な場合が多い．われわれは内視鏡検査および胃生検にて術前にIIb型早期胃癌と診断しえた2症例（典型Ⅱb1例，類似Ⅱb1例）を経験したので報告する．

　We consider that typical Ⅱb early gastric cancer has two features, i.e., the lesion could not be identified as such by macroscopic observation of the surface of the resected specimen and macroscopically the cut surface of the lesion is flat. A Ⅱb-like lesion is considered as those that satisfy either of the two features. Of 505 cases (543 lesions) of all early gastric cancers histologically confirmed in our department, Ⅱb cancer was found in nine cases (nine lesions). Solitary Ⅱb was seen in two cases and concomitant Ⅱb in seven. In this paper are illustrated two cases of solitary Ⅱb preoperatively diagnosed by endoscopy and biopsy.

　Case1: A46-year-old man visited us because of some abnormality in the angle and on the greater curvature of the antrum detected by periodical health checkup. Endoscopic examination of the stomach showed granular changes of various size on the mucosal surface on the greater curvature of the antrum, but it was difficult to discriminate them from those due to gastritis. Cancer cells were positive in only one biopsy specimen out of six obtained from that part, Under a diagnosis of Ⅱb gastrectomy was performed, Granular changes were seen also on the greater curvature of the antrum of the excised specimen, but macroscopically any cancer lesion could not be discriminated. Histologically cancer lesion was seen within the granular mucosal surface of the greater curvature of the antrum. The lesion measured 0.8 by 0.8cm, with m degree of depth invasion. Histological diagnosis was moderately differentiated tubular adenocarcinoma. The cut surface was flat even when seen with high-power loupe.

　Case2: A 72-year-old man was placed on the follow-up list because of ulcer scar in the area of the angle. During the course of observations a reddened fleck of irregular shape was seen by endoscopy on the lesser curvature of the angle. As biopsy revealed cancer cells, gastrectomy was performed. In the resected specimen the border between the cancerous part and the normal mucosa was indistinct and the extent of the lesion could hardly be distinguished. However, with the help of drawing of the mucosal architecture, the lesion was to be confirmed (ow+). It measured 3.5 by 2.0cm with m degree of depth invasion. Histologically it was moderately differentiated tubular adenocarcinoma. As the cut surface was flat seen with a loupe, we considered the lesion as Ⅱb-like cancer.