9 things to know about neuroendocrine tumors

About 12,000 people will be diagnosed with neuroendocrine tumors — sometimes called carcinoid tumors — each year. But what exactly are these tumors, where are they typically found and are they cancerous? We spoke with neuroendocrine tumor specialist Daniel Halperin, M.D., to learn more. What are neuroendocrine tumors, and where are they usually found? While the name “neuroendocrine” implies that these tumors involve both nerve cells and hormones, they are mainly thought to come from endocrine cells. The “neuro-” is more of a quirk of history. Basically, neuroendocrine tumors are cancers that can develop anywhere endocrine cells are present. Endocrine cells help regulate various body functions, such as growth, reproduction and metabolism. They are distributed throughout the body, but the most common places for tumors to develop from them are in the lungs, small intestines and pancreas. Are all neuroendocrine tumors cancerous? The short answer is yes. In some of the older systems for classifying neuroendocrine tumors, pathologists would describe them as either “benign” (non-cancerous) or “malignant” (cancerous), based on the appearance of the tumor cells under a microscope. Unfortunately, those terms did not always accurately reflect whether the tumor would metastasize and behave aggressively or not. Now, all neuroendocrine tumors are considered malignant. There are just shades of gray in terms of how aggressive they are. Some spread really easily. Others do not. But we consider all of them cancer. What are the most common symptoms of neuroendocrine tumors? We tend to see neuroendocrine symptoms in two categories: Hormonal: These include severe diarrhea, severe gastric ulcers, or uncontrolled blood sugar that respond poorly to treatment. The hormones produced...