Monarch Disease Ontology term MONDO_0006257 (jejunal neuroendocrine tumor G1) is a well differentiated, low grade neuroendocrine tumor (carcinoid tumor) that arises from the jejunum. 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: carcinoid tumor of jejunum, carcinoid tumor of the jejunum, carcinoid tumour of jejunum, carcinoid tumour of the jejunum, grade 1 neuroendocrine neoplasm of jejunum, jejunal NET G1, jejunal carcinoid tumor, jejunal carcinoid tumour.