Neuroendocrine tumor can cause a wide array of symptoms depending on the type of tumor and its location. Some tumors produce symptoms as a result of hormone secretion whereas others cause symptoms related to tumor growth. Therefore, symptoms can vary quite widely depending on tumor locations and type of hormone produced.
Symptoms can include:
- Crampy abdominal pain, sometimes associated with nausea and vomiting
- Fullness in the abdomen
- Feeling of fullness in the abdomen
- Redness or a feeling of warmth in the neck or face
- Fatigue
- Shortness of breath
- Wheezing
- Diarrhea
- Swelling in the feet or ankles
- Pain or a feeling of fullness in the abdomen
- Gastrointestinal bleeding or black bowel movements
- Dizziness, fainting or tremors related to low blood sugars
What to do if you’re experiencing neuroendocrine cancer symptoms

If you suspect that you might have a neuroendocrine tumor, it’s important to not delay seeking a professional opinion, since these tumors can have a number of long-term effects on the body if left untreated. Your first step will likely be to reach out to your primary care provider, who can assess your condition through a physical examination and order any necessary diagnostic tests. Some of the tests used to diagnose a neuroendocrine tumor include:
- Biopsy – This procedure—which involves removing a small portion of tissue from the patient’s body and then sending it to a laboratory for testing—is one of the most reliable methods for diagnosing a neuroendocrine tumor. Notably, if your physician suspects that you have a pheochromocytoma (a rare neuroendocrine tumor affecting the adrenal glands), he or she will likely order a biopsy only if it’s absolutely necessary to confirm your diagnosis, since performing a biopsy on this type of tumor could be life-threatening.
- Blood/urine test – Because neuroendocrine tumors can cause the body to produce excess hormones, physicians will often order blood and/or urine testing to measure the patient’s hormone levels. For example, since neuroendocrine tumors can secrete serotonin, a physician might order a urine test to measure the level of hydroxyindoleacetic acid (5-HIAA), which is a breakdown product of serotonin.
- Endoscopy – During an endoscopy, a clinician inserts a long, flexible tube (endoscope) through an opening in the patient’s body. The tube will have a light and a camera attached to it so that the practitioner can see inside. The spot where the tube is inserted will depend on where the suspected tumor is located. If a tumor is thought to be in the patient’s esophagus, for example, the physician will likely insert the tube through the patient’s mouth. But if the tumor is suspected to be in the patient’s colon, then the tube will likely be inserted through his or her anus.
- Positron emission tomography (PET) scan – During a PET scan, the provider injects a small amount of a radioactive drug (tracer) into a vein in the patient’s arm. Once the injection is complete, the patient undergoes a scan to determine where the tracer has collected within his or her body.
- Other imaging tests – Physicians often order ultrasounds and X-rays to create detailed images of a suspected neuroendocrine tumor.
If it turns out that you do have a neuroendocrine tumor, the results of these tests will also be helpful in determining how far the malignancy has progressed. For example, the results may show whether the tumor has spread (metastasized) to another area of your body.
Treatment for neuroendocrine tumors at Moffitt Cancer Center
In Moffitt Cancer Center’s Gastrointestinal Oncology Program, our neuroendocrine tumor team will assess a patient’s symptoms carefully and conduct a series of tests. If a diagnosis has been made, our multispecialty team will devise an individualized treatment plan and monitor the patient’s progress closely. We also offer innovative new treatments through our robust clinical trials program.
If you’re concerned about possible neuroendocrine tumor symptoms or want to learn more about treatment strategies, contact Moffitt Cancer Center by calling 1-888-663-3488, or by filling out our online new patient registration form. We’re pleased to offer a rapid initial turnaround, connecting new patients to a cancer expert as soon as possible.