Mixed neuroendocrine-non-neuroendocrine neoplasms of the digestive system: A mini-review

Figure 4 Histopathology of a mixed neuroendocrine-non-neuroendocrine neoplasm of colon. A: Hematoxylin and eosin (H&E) stain of mixed neuroendocrine-non-neuroendocrine neoplasm. On the right side is a well-differentiated invasive adenocarcinoma. On the left side is a poorly differentiated neuroendocrine carcinoma (20 ×, H&E); B: The adenocarcinoma component is positive for cytokeratin 20, but the neuroendocrine component is negative (20 ×); C: Positive synaptophysin staining in the neuroendocrine component but negative staining in the adenocarcinoma component (20 ×); D: Positive CDX2 staining in both adenocarcinoma and neuroendocrine carcinoma components (20 ×); E: Merging area of adenocarcinoma and neuroendocrine carcinoma components (20 ×); F: Positive synaptophysin staining of neuroendocrine cells in the merged area (20 ×).