小さな未分化型胃癌の診断の実態

The Actual Stage of Diagnosis of the Small Undifferentiated type Cancer of the Stomach.

要旨　胃癌697例（749病変）のうち，1cm以下の小さな未分化型胃癌33病変を対象に，臨床診断の実態について検討した．①5mm以下の未分化型微小胃癌の頻度は全切除胃癌に対して1.3％であった．②癌組織型と大きさの関係では，大きさが10mmを超えると癌組織型差はほとんどなかった．③臨床発見成績は微小胃癌30％（3/10病変），小胃癌91％（21/23病変）であった．④微小胃癌の肉眼型はⅡbあるいはそれに近い形態が多かった．未分化型微小胃癌が極端に少ない理由は，平均年齢が50歳台にあり，加齢に伴う背景粘膜の質的変化と癌組織発生の関係から理解できた．未分化型微小胃癌を臨床的に発見するには，標的年齢を40歳台に置くべきであり，背景粘膜の質と癌組織型の関係を考慮に入れた検査が必要である．

　Out of 679 cases of gastric cancer (749 lesions), 33 lesions of the small undifferentiated type of less than 1 cm in size were evaluated for the actual state of clinical diagnosis. 1) The frequency of the minute undifferentiated type cancer of the stomach of less than 5 mm in size was 1.3% to all the removal cancer of the stomach. 2) When the size of the lesion exceeded 10 mm, there was almost no relationship between the size and histological types. 3) The clinical detection rates of minute and small gastric cancers were 30% (3 out of 10 lesions) and 91% (21 out of 23 lesions) respectively. 4) Most of the macroscopic shapes of minute gastric cancer were type IIb or its similar shape. The reason why undifferentiated type gastric cancer was extremely rare could be explained by the average age of the patients was 50-year-old era and the relation between the qualitative change of the background mucosa by aging and the cancer development. To discover minute undifferentiated type gastric cancer clinically, the target age should be placed in the 40-year-old era and the relation between the quality of the background mucosa and the histologic type of cancer should be taken into consideration while examinations.