colorectal neuroendocrine tumor G1 (Monarch Disease Ontology identifier MONDO_0006162) is a well differentiated, low grade neuroendocrine tumor (carcinoid tumor) that arises from the colon or rectum. The mitotic count is less than 2 per 10 HPF and/or the Ki67 index is equal to or less than 2 percent. Also known as: colorectal NET G1, colorectal carcinoid tumor, colorectal carcinoid tumour, colorectum NET G1, colorectum carcinoid tumor, colorectum carcinoid tumour, colorectum neuroendocrine neoplasm G1, colorectum neuroendocrine tumor, well differentiated, low grade.