Neuroendocrine Lung Cancer. ln the lung, neuroendocrine cancer can arise from the carcinoid cells, or it can appear as small cell lung cancer (SCLC) or large cell neuroendocrine carcinoma. Carcinoid cancer often secretes hormones—usually serotonin—that cause side effects like flushing and difficulty breathing. They are spread throughout the body. Neuroendocrine cells are like nerve cells (neurons), but they also make hormones like cells of the endocrine system (endocrine cells). They receive messages (signals) from the nervous system and respond by making and releasing hormones. These hormones control many body functions. Neuroendocrine cells are found in almost every organ of the body. They are mainly found scattered in the gastrointestinal (GI) tract (including the small intestine, rectum, stomach, colon, esophagus and appendix), the gallbladder, the pancreas (islet cells) and the thyroid (C cells).