CD200 and neoplasm: Of note, both neoplasms were negative for the classic neuroendocrine markers chromogranin-A and synaptophysin; for different types of cytokeratin, such as cytokeratin 7, cytokeratin 20, and cytokeratin AE1/AE3; for the acinar markers BCL10 and trypsin; and for some solid pseudopapillary markers such as CD200, progesterone receptor, and vimentin.