Esophagogastroduodenoscopy of a 45-year-old woman revealed a submucosal tumor in the gastric antrum. Endoscopic submucosal dissection of the tumor was performed. The histological findings revealed a fibromyxomatous tumor composed of myofibroblastic cells with no evidence of malignancy. The growth pattern of the resected specimen was not multinodular or plexiform. We therefore tentatively referred to the present tumor descriptively as a gastric uninodular fibromyxomatous tumor, stressing its singular nodularity. It was initially roughly 10 mm in size but grew over a period of 4 years. A uninodular plexiform fibromyxoma might increase in size but might not become multinodular if it remains small.
Keywords: endoscopic submucosal dissection; mesenchymal mass; myofibroblastic cell.