When it comes to neuroendocrine tumors, most people will be unfamiliar with them. But for Apple founder Steve Jobs, the man who invented the iphone and changed the world, I believe everyone is familiar with it. 2011, just a day after the release of the new generation of iphone, this great man passed away sadly. For the disease that took his life, there were many people who thought it was pancreatic cancer, but it was actually a rare tumor —- neuroendocrine tumor. The naming of the disease neuroendocrine tumor is very special, what kind of class of disease is it? As the name suggests, neuroendocrine tumors are tumors that originate from neuroendocrine cells, which are found all over the body and can produce a variety of hormones. Therefore, neuroendocrine tumors can occur anywhere in the body, but they are most common in the digestive organs such as the stomach, intestines and pancreas, accounting for about 2/3 of cases. The incidence of this disease has increased fivefold in the last 30 years and is therefore gaining attention. What are the causes of neuroendocrine tumors? Who is susceptible to the disease? The exact cause of neuroendocrine tumors is not known. Most of these tumors are disseminated, and there is no gender difference in their onset. However, a small percentage of neuroendocrine tumors are associated with genetic factors, such as multiple endocrine adenomas. What are the symptoms of neuroendocrine tumors? What are the symptoms that indicate the presence of this disease? Neuroendocrine tumors can be divided into two categories: non-functional (about 80%) and functional (about 20%). Functionality refers to the ability of tumor cells to secrete corresponding hormones and cause hormone-related clinical symptoms. For example, tumors secreting pentraxin, a hormone, can cause skin flushing, asthma and diarrhea; tumors secreting insulin can cause hypoglycemia; tumors secreting gastrin can cause refractory peptic ulcers and diarrhea; tumors secreting glucagon can cause diabetes, etc. Since there are more than 40 different hormone-secreting neuroendocrine cells in the human body, the symptoms of functional neuroendocrine tumors are quite complex and diverse. Non-functional neuroendocrine tumors do not secrete hormones, and clinically they mainly manifest various symptoms caused by tumor occupancy, such as dysphagia, abdominal pain, abdominal distension, abdominal mass, jaundice or black stool. There are also quite a number of non-functional neuroendocrine tumors that are discovered accidentally during physical examination. What diseases are neuroendocrine tumors easily misdiagnosed as? Since the clinical manifestations of most neuroendocrine tumors are not characteristic, it is difficult to obtain early diagnosis by symptoms alone. Therefore, misdiagnosis cases are not uncommon. For example, insulinoma with hypoglycemic symptoms is often misdiagnosed as a neurological disease, while gastrinoma may be diagnosed as a common peptic ulcer. In addition, most clinicians are not aware of the disease and fail to choose the best treatment plan for the patient, thus the patient may miss the best time to treat the disease.