Neuroendocrine tumour of the descending part of the duodenum complicated with schwannoma: A case report

Figure 1 Endoscopic resection of the tumour. A: Tumour in the descending part of the duodenum in the natural state; B: Using endoscopic ultrasonography to explore the tumour; C: Endoscopic electrocoagulation for resection of the tumour; D: A titanium clip was used to clamp the wound to stop the bleeding.

Figure 2 Pathological manifestation of the tumour under a light microscope. A: Pathological tissue (Magnification: 100 ×). The lower right corner is the nesting tissue of the schwannoma, and the rest is the vesicle-like tissue of the neuroendocrine tumour; B: Neuroendocrine tumour tissue (Magnification: 200 ×); C: Schwannoma tissue (Magnification: 200 ×); D: The vertical incisal margin was negative, and there was no lymphatic vascular invasion (Magnification: 400 ×).

Figure 3 Immunohistochemical neuroendocrine tumour results. A: CD56⁺ (Magnification: 200 ×); B: Chromogranin A+ (Magnification: 200 ×); C: Desmin+ (Magnification: 400 ×); D: Synaptophysin+ (Magnification: 200 ×).

Figure 4 Immunohistochemical results. A: S100+ expression in schwannoma (Magnification: 200 ×); B: The antigen KI-67 index of the neuroendocrine tumour was approximately 1% (Magnification: 200 ×); C: The KI-67 index of the schwannoma was approximately 1% (Magnification: 200 ×).