IgG4-related Sclerosing Disease Forming a Gastric Submucosal Tumor Diagnosed after Laparoscopic Endoscopic Cooperative Surgery—Report of a Case—

Abstract

A 65-year-old woman was referred to our hospital for a gastric submucosal tumor which was detected by upper GI series at a medical checkup. Upper gastrointestinal endoscopy showed a tumor 15 mm in size located in the antrum of the stomach. Endoscopic ultrasound revealed a hypoechoic mass 13 mm in diameter arising from the fourth layer of the gastric wall. Contrast enhanced CT scan showed a 10-mm well-defined, enhancing mass at the anterior wall of the stomach antrum without lymph node invasion and distal metastasis. The preoperative diagnosis was gastrointestinal stromal tumor (GIST), and laparoscopic and endoscopic cooperative surgery (LECS) was performed. Pathological findings showed fibrosis of muscularis propria infiltrated by IgG4-positive plasma cells. The IgG4-positive cell/IgG-positive cell ratio was around 40%. IgG4-related sclerosing disease of the stomach was diagnosed. We herein report a rare case of IgG4-related sclerosing disease forming a submucosal tumor.