A case of esophageal granular cell tumor diagnosed by mucosal incision-assisted biopsy.

For an esophageal submucosal mass suspicious of granular cell tumor (GCT) based on gross appearance and endoscopic ultrasound findings, a sufficient number of biopsy specimens is required for a definite diagnosis using immunohistochemical examination. When the specimen obtained by forceps biopsy is insufficient, endoscopic ultrasound-fine needle aspiration (EUS-FNA) is believed to be an useful alternative. However, it may be difficult to obtain an adequate amount of tumor material using EUS-FNA. Mucosal incision-assisted biopsy (MIAB) is a simple method that can collect larger amounts of specimens. This procedure is helpful for physicians who encounter the problem of obtaining an adequate amount of biopsy material from esophageal tumors suspicious for GCT. We present a case of esophageal GCT that was successfully diagnosed through MIAB.