Neuroendocrine tumors (NETs) are a diverse group of tumors that arise from neuroendocrine cells, which are found throughout the body. These cells produce hormones and are involved in regulating various bodily functions. NETs can occur in different organs, including the pancreas, lungs, and gastrointestinal tract, and can vary in their behavior from benign to malignant. Symptoms of NETs depend on their location and whether they produce hormones. Some common symptoms may include abdominal pain, changes in bowel habits, or unexplained weight loss. Diagnosis often involves imaging tests, blood tests, and sometimes biopsy. Treatment options may include surgery, chemotherapy, or targeted therapies.