Fig. 1

A, B Histopathological images of typical neuroendocrine neoplasm (G1) in a 66-year-old female patient. The lesion is located at the top of the appendix. The nucleus is round, uniform in size and staining, indistinct in boundary, and arranged in nests or bands. No vascular, lymphatic, or neural invasion was observed. There is no tumor invasion of the appendix mesentery. Tumor cells were not found at the surgical margin (hematoxylin and eosin stain; original magnification × 100 and × 200)