A well differentiated, low grade neuroendocrine tumor (carcinoid tumor) that arises from the rectum. The mitotic count is less than 2 per 10 HPF and/or the Ki67 index is equal to or less than 2 percent. The disease is MONDO_0021534 (rectal neuroendocrine tumor G1). Also known as: carcinoid of rectum, carcinoid of the rectum, carcinoid tumor of rectum, carcinoid tumor of the rectum, carcinoid tumour of rectum, carcinoid tumour of the rectum, grade 1 neuroendocrine neoplasm of rectum, rectal NET G1.