Colorectal neuroendocrine carcinoma: A case report and review of the literature

Figure 2 Histological findings of the tumor. A: Hematoxylin-eosin staining showed that the tumor cells were poorly differentiated; B: Complicated with the intratumoral bleeding; C: Tumor cells underwent immunohistochemical staining for Synaptophysin. Black arrows indicate the positively stained cells; D: A high proliferative fraction of immunohistochemical staining for Ki67 staining. Black arrows indicate the positively stained cells.