A gastric glomus tumor resected using non-exposed endoscopic wall-inversion surgery

Gastric glomus tumors are extremely rare, constituting approximately 1% of gastric mesenchymal tumors. We report the case of a 45-year-old female patient in whom upper gastrointestinal endoscopy revealed a 3-cm submucosal tumor with a bridging fold in the posterior wall of the antrum of the stomach. Contrast-enhanced computed tomography revealed the tumor to be hypervascular in the arterial phase and exhibit continuous enhancement in the post-venous phase. Dynamic contrast-enhanced magnetic resonance imaging showed that the tumor was hypervascular in the early phase and persistently enhanced in the late phase. Endoscopic ultrasonography revealed a mosaic echo pattern. Endoscopic ultrasound-guided fine-needle aspiration biopsy was performed. Immunohistochemical examination revealed that the tumor was positive for α-smooth muscle actin and synaptophysin, but negative for CD56, chromogranin A and C-kit. Furthermore, 1-2% of the tumor cell nuclei were Ki-67-positive. Thus, the preoperative diagnosis was a benign glomus tumor. The patient then underwent non-exposed endoscopic wall-inversion surgery (NEWS), and the tumor was completely resected. In conclusion, NEWS is an effective method for the treatment of gastric glomus tumors.