Appendiceal adenocarcinoma arising from serrated lesions: A case report

Figure 1 Contrast-enhanced abdominal computed tomography findings. Computed tomography scan showing an elongated and thickened appendix without obvious lymphadenopathy or distant metastases.

Figure 2 Endoscopic ultrasound showing a mixed hypoechoic lesion at the appendiceal orifice. A: White-light endoscopy; B: Endoscopic ultrasound image.

Figure 3 Intraoperative endoscopic images. A and B: Full-thickness resection; C and D: Closure of defect with metal clips; E and F: Excised specimen.

Figure 4 Histopathology and immunohistochemistry. A: Hematoxylin and eosin stain showing crypt branching and serrated morphology (× 40); B: Diffuse cytokeratin 20 positivity (× 40); C: Asymmetric Ki-67 expression (× 40); D: Hematoxylin and eosin stain showing crypt branching and serrated morphology (× 100); E: Diffuse cytokeratin 20 positivity (× 100); F: Asymmetric Ki-67 expression (× 100).