lung cancer cell neuroendocrine tumor cell pulmonary neuroendocrine tumor cell 2014-03-09T15:37:19Z BTO:0005605 BrendaTissueOBO Marion Neuroendocrine tumors (NETs) are neoplasms that arise from cells of the endocrine (hormonal) and nervous systems. Many are benign, while some are malignant. They most commonly occur in the intestine, where they are often called carcinoid tumors, but they are also found in the lung and the rest of the body.