2020 Volume 59 Issue 6 Pages 311-317
Background : Gastric schwannoma is a rare submucosal tumor, accounting for 0.2% of all gastric tumors, and it is difficult to clinically differentiate this tumor from GIST (gastrointestinal stromal tumor) and leiomyoma. We encountered two cases of gastric schwannoma with in which we performed endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Herein we report the cytological features of gastric schwannoma and the differential diagnosis of this tumor from other gastric submucosal tumors.
Cases : Two women, one in her 50 s and the other in her 70 s, were diagnosed as having gastric submucosal tumors, measuring 15 mm in diameter. In both cases, the tumors increased in size during follow-up. Therefore, EUS-FNA was performed, and in both cases, cytological and histological examinations using cell block specimens revealed spindle cells with pale eosinophilic cytoplasm, and a positive result of immunohistochemistry for S-100. Therefore, the tumors in both cases were diagnosed as gastric schwannomas. The resected surgical specimens showed similar histological findings, confirming the diagnosis of gastric schwannoma.
Conclusion : Although it is difficult to confirm the diagnosis of gastric schwannoma by cytology alone, we consider that the elliptical tumor cell nuclei, short cell bundles, cellular protrusions from clusters, and presence of numerous lymphocytes and crushed nuclei in the background are suggestive of gastric schwannoma, and that therefore, it might be possible to surmise the histological type by EUS-FNA.
