典型像を呈したⅡa型sm胃癌の1例と深達度診断についての検討

A Typical Case of Early Gastric Cancer, Type Ⅱa, with Submucosal Invasion and Investigation of 48 Ⅱa Lesions about Depth of Invasion

　隆起型早期胃癌のうち深達度smの癌は，リンパ節転移，肝転移がしばしばみられ，深達度mの癌との鑑別が臨床上重要である．今回，深達度smのⅡa型早期胃癌の1例を呈示し，文献的および，われわれの施設で経験したⅡa型早期胃癌の深達度診断に関して若干の検討を加えたので報告する．

　A 48-year-old woman was admitted to our hospital on October 16, 1972, complaining of anorexia. She had already been diagnosed to harbor gastric cancer at a certain hospital by gastrofluoroscopy, endoscopy and histopathological examination. Laboratory studies on admission revealed anemia and mild liver dysfunction. X-ray examination of the stomach showed a slightly elevated lesion, measuring about 3 cm in diameter, on the posterior wall of the upper body. The lesion was lobulated and its surface showed granular pattern of various size larger than the areae gastricae and irregular arrangement of the granules. White coating and bleeding were observed partially by endoscopy. Judging from these findings we diagnosed this lesion as Ⅱa with submucosal invasion, and proximal partial gastrectomy with splenectomy was performed. Pathological examination revealed that Ⅱa lesion was composed of adenocarcinoma with well differentiated tubular structure, invading the submucosal layer.

　We investigated 36 cases of Ⅱa lesions with mucosal invasion and 12 cases of Ⅱa lesions with submucosal invasion we have experienced. Some features of Ⅱa lesions with submucosal invasion were as follows; 1) Most of the lesions were larger than 2 cm in diameter. 2) The lesion was frequently lobulated and the surface showed irregular granular pattern and small erosions were occasionally observed. 3) White coating and bleeding were often seen on its surface by endoscopy. 4) The height of the lesions tended to be higher than Ⅱa with mucosal invasion. We also examined two groups of Ⅱa lesions with submucosal invasion which were divided by the degree of submucosal invasion. The frequency of small erosions and easy bleeding was higher as the degree of submucosal invasion was extensive. Compared with no lymph node metastasis in Ⅱa with mucosal invasion, it was found in 25% of Ⅱa with submucosal invasion. Therefore, it is very important that the degree of invasion of early gastric cancer is correctly established.