Figure 4.

Pathological analysis of the gastric mass confirmed a gastric schwannoma through positive immunohistochemical staining for S-100 protein and vimentin, whereas CD117, CD34, β-catenin, smooth muscle actin, synaptophysin, chromogranin and desmin were negative. A: The tumor showed typical features of a spindle cell tumor with moderate nuclear pleomorphism but no mitotic activity (original magnification: × 200); B: S-100 protein immunostaining demonstrated strong nuclear and cytoplasmic immunoreactivity; C: Vimentin protein immunostaining demonstrated strong cytoplasmic immunoreactivity.