Comprehensive evaluation of rare case: From diagnosis to treatment of a sigmoid Schwannoma: A case report

Figure 1 Colonoscopy reveals a submucosal protrusion located 15 cm from the anus.

Figure 2 Ultrasound endoscopy displays a hypoechoic mass at the lesion, which is located in the lamina propria, with heterogeneous echogenicity, about 1. 0 cm in size.

Figure 3 The Hematoxylin and eosin staining demonstrates the presence of spindle-shaped anisotropic cells exhibiting an intact peritoneum and the absence of extraperitoneal invasion.

Figure 4 CD34, CD117, SMA, Dog-1 are negative in tumor cells. A: CD34 is negative in tumor cells, while normal vascular structures are stained; B: CD117 is negative in tumor cells; C: SMA is negative in tumor cells; D: Dog-1 is negative in tumor cells.

Figure 5 SOX10 and S100. A: S-100 is diffusely strongly positive in tumor cells; B: SOX-10 is strongly positive in tumor cells. SOX10 and S100 are positive. The immunohistochemical staining exhibits a consistent dark brown color.

Figure 6 Tumor. A: Tumor of about 1.0 cm in size ; B: Tumor is observed as unencapsulated yellowish material.