Long-term survival with multimodal treatment including conversion surgery for locally advanced esophageal neuroendocrine carcinoma: A case report

Figure 5 Histological and immunohistochemical findings. A and B: Type 3 tumor located in the middle thoracic esophagus with the depth of invasion classified as T2 (muscularis propria); C: Cross-sectional hematoxylin and eosin staining showing the tumor structure; D: Magnified view of the area indicated by the square in panel C; E: Hematoxylin and eosin staining reveals a large-cell type of neuroendocrine carcinoma, with no coexistence of squamous cell carcinoma at × 400 magnification; F: Ki-67 staining was positive in more than 90% of tumor cells, indicating a high proliferative index; G-I: Immunohistochemical analysis showed that the tumor stained positively for CD56, but not synaptophysin or chromogranin A.