スキルス胃癌と鑑別を要する非腫瘍性疾患―胃蜂窩織炎

Phlegmonous Gastritis

要旨　胃蜂窩織炎は，粘膜下層を中心に胃壁全層にわたる炎症・浮腫を来す比較的まれな非特異的化膿性炎症性疾患である．成因別に原発性，続発性，特発性に分類され，起因菌としては連鎖球菌が最も多いとされている．急性腹症との鑑別目的に腹部CTが施行され，胃壁の肥厚から本症が疑われることが多い．腫大した皺襞や胃壁の伸展不良を認め，スキルス胃癌との鑑別が必要になることがあるが，通常は急激な臨床経過をとることから鑑別は比較的容易である．生検による膿汁流出，組織・胃液培養による細菌の証明，超音波内視鏡などが診断に有用である．まれではあるが慢性に経過する胃蜂窩織炎が存在し，スキルス胃癌と誤診されることがある．

　Phlegmonous gastritis（PG）is a nonspecific suppurative inflammation disease arising from the submucosal layer, and extending to the full thickness of the stomach. PG is categorized as primary, secondary or idiopathy according to etiology. Streptococcus spp. are the most common pathogens responsible for PG. The finding of a thickening of the gastric wall in abdominal CT is useful in the differential diagnosis of this acute abdominal condition. Upper gastrointestinal endoscopy reveals giant folds and a poorly distensible gastric wall, so these findings are similar to the ones of scirrhous gastric cancer（SGC）. To distinguish between PG and SGC, we should pay attention to the differences in findings of the clinical symptoms and courses, blood examinations, endoscopy, endoscopic ultrasonography, and histological examination of biopsy specimens. It is usually easy to make a diagnosis of acute type-PG, but some patients with chronic type-PG who were misdiagnosed as SCG and received gastrectomy have been reported. Chronic type-PG is rare, but we must keep it in consideration because chronic type-PG shows similar clinical symptoms and courses to SGC.