Abstract
The patient was a 56 year-old male, in whom SMT on the lesser curvature of the upper body of the stomach had been revealed 2-years previously. EUS findings showed a homogeneous low echoic tumor in the 3rd layer of the gastric wall which was connected with the 4th layer, therefore he was followed-up as having leiomyoma of the stomach. Two years later, EUS with a 20 MHz probe showed a heterogeneous tumor with irregular shape and a marginal line the echogenicity of which was higher than the 3rd layer. These findings contradicted the previous diagnosis of leiomyoma. A boring biopsy was performed based on which a diagnosis of granular cell tumor (GCT) was made. Endoscopic resection (the ESD method) was done following the patient's strong wishes, though an operation was recommended. During ESD, we confirmed that the tumor had adhered to the muscularis propria. Histopatho;logical examination of the resected specimen revealed that the tumor was 9 mm×8 mm at the vertical excision side. Histological examination showed that the tumor was a GCT which was positive for S-100 protein and NSE. P53 immunohistological staining was negative and MIB-1 labeling index was 1% or less, therefore the GCT was diagnosed as benign.
