Some symptoms of neuroendocrine carcinoma include headache, diarrhea, loss of appetite, anxiety and gastric ulcer disease. Neuroendocrine tumors are quite rare and account for less than 1 percent of malignant disorders in the United States, notes University of Pittsburgh Medical Center.
Neuroendocrine carcinomas can originate from various locations of the body, including the lungs, gastrointestinal tract and brain. Individuals with this condition often experience persistent, painful sensations in one area of the body. While some individuals may suddenly start gaining weight, other cases cause sudden, unexplained weight loss.
This condition may lead to hoarseness and development of a persistent cough. Thickening or formation of a lump can be observed in any part of the body. Neuroendocrine carcinomas may lead to a yellowing of the skin, which is usually referred to as jaundice. Unusual bleeding or discharge from the body can also be part of the symptoms that develop.
Other symptoms include persistent fever or nights sweats, anxiety, change in bowel or bladder movement, hypoglycemia and hyperglycemia. Doctors diagnose this condition by recording patient medical history, asking about the symptoms and performing a physical examination, states the National Cancer Institute. Pathologists ascertain the condition by taking a tissue sample and examining it with the aid of stains that help clarify the cells' subtype.