A case of a granular cell tumor of the stomach with gradual enlargement during a 30 month-follow-up

A 46-year-old woman with a gastric submucosal tumor (SMT) had been followed up with endoscopy for 30 months in our hospital. The SMT showed gradual enlargement during the follow-up period. EUS revealed the submucosal layer was maintained beneath the SMT which was located between the mucosa and submucosa. Because malignancy could not be ruled out, endoscopic submucosal dissection (ESD) was performed for the purpose of a "total biopsy" and the lesion was resected en bloc. Immunohistochemical findings revealed that the tumor was negative for SMA, KIT, CD34, and positive for S-100. It was also positive for PAS stain. The MIB-1 index was around 5%. Thus, the tumor was pathologically diagnosed as a benign granular cell tumor of the stomach. We conclude that the combination of EUS and ESD is useful for the diagnosis and treatment of SMTs above the submucosal layer such as granular cell tumors.