Abstract:

Objective: To investigate the clinicopathological characteristics of gastric schwannomas (GSs). Methods: The 31 GS cases, including 12 males and 19 females with a median age of 51 years (22-70), of 17 223 surgical procedures performed from January 2014 through March 2020 were retrieved for histological and immunological studies. The diagnosis, differentiation, treatment and prognosis were discussed with reference to relevant literatures. Results: The pre-operative imaging study suggested gastrointestinal stromal tumor(GIST) in 20 cases. Only two patients had the tumor breaking the serosa, and the tumor found on 29 patients was located between the muscularis propria and serosa of the stomach. Histological examination revealed well-circumscribed tumor with a prominent peripheral lymphoid cuff. The tumor was mainly composed with spindle cells, arranged in bundles and small clusters or in a haphazard fashion. The common features of soft tissue schwannoma, such as Antoni A zone and Antoni B zone, were absent or rarely found. Although the atypical nucleus could be identified, the mitosis was rare or absent. GS were diffusely positive for S100 and SOX10. Conclusions: GS is a rare benign mesenchymal tumor of the stomach, most of which are easy to be misdiagnosed as gastrointestinal stromal tumor. The diagnosis should be established based on histological features and immunophenotypes.

Key words: Gastric, Schwannoma, Differential diagnosis, Immunohistochemistry