Acute phlegmonous gastritis is a rare disorder in which bacterial infection
occurs in the gastric wall. Gastrectomy involving the affected area has be
en thought to be an effective form of treatment. The authors report a case
of a 32-year-old woman who had severe upper abdominal pain without signs of
peritoneal irritation. Endoscopy showed edematous and reddened gastric muc
osa with a mass lesion in the gastric antrum. Endoscopic ultrasonography sh
owed thickening of the antral wall and a low-echoic mass in the gastric ant
rum, thought to represent a fluid collection. White pus was aspirated from
the mass. Localized type of acute phlegmonous gastritis with a gastric absc
ess was diagnosed. Culture of the pus showed Streptococcus pneumoniae. Thro
ugh early diagnosis without laparotomy, the patient's gastritis was success
fully treated with antibiotics alone.