Neuroendocrine tumors

Neuroendocrine cancer | 2019-10-09 03:02:03


Neuroendocrine tumors are cancers that begin in specialized cells called neuroendocrine cells. Neuroendocrine cells have traits similar to those of nerve cells and hormone-producing cells.

Neuroendocrine tumors are rare and can occur anywhere in the body. Most neuroendocrine tumors occur in the lungs, appendix, small intestine, rectum and pancreas.

There are many types of neuroendocrine tumors. Some grow slowly and some grow very quickly. Some neuroendocrine tumors produce excess hormones (functional neuroendocrine tumors). Others don't release hormones or don't release enough to cause symptoms (nonfunctional neuroendocrine tumors).

Diagnosis and treatment of neuroendocrine tumors depend on the type of tumor, its location, whether it produces excess hormones, how aggressive it is and whether it has spread to other parts of the body.


  1. Adrenal cancer
  2. Carcinoid tumors
  3. Islet cell cancer
  4. Merkel cell carcinoma
  5. Paraganglioma
  6. Pheochromocytoma


Neuroendocrine tumors don't always cause signs and symptoms at first. The symptoms you might experience depend on the location of your tumor and whether it produces excess hormones.

In general, neuroendocrine tumor signs and symptoms might include:

Neuroendocrine tumors that produce excess hormones (functional tumors) might cause:

When to see a doctor

Make an appointment with your doctor if you have any persistent signs and symptoms that worry you.


The exact cause of neuroendocrine tumors isn't known. These cancers begin in neuroendocrine cells that have traits similar to those of nerve cells and hormone-producing cells. Neuroendocrine cells are found throughout your body.

Neuroendocrine tumors begin when neuroendocrine cells develop changes (mutations) in their DNA. The DNA inside a cell contains the instructions that tell the cell what to do. The changes tell the neuroendocrine cells to multiply rapidly and form a tumor.

Some neuroendocrine tumors grow very slowly. Others are aggressive cancers that invade and destroy normal body tissue or spread (metastasize) to other parts of the body.

Risk factors

The risk of neuroendocrine tumors is higher in people who inherit genetic syndromes that increase the risk of cancer. Examples include:

By Mayo Clinic Staff

Neuroendocrine tumors care at Mayo Clinic

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  1. Neuroendocrine and adrenal tumors. Plymouth Meeting, Pa.: National Comprehensive Cancer Network. Accessed June 4, 2019.
  2. Neuroendocrine tumors: Introduction. Accessed June 6, 2019.
  3. Warner KJ. Allscripts EPSi. Mayo Clinic, Rochester, Minn. April 29, 2019.


Neuroendocrine tumors

Neuroendocrine tumor

Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

North American Neuroendocrine Tumor Society has published several consensus guidelines relating to the medical treatment and management of neuroendocrine . Guidelines are developed pursuant to National Institute of Health (NIH) standards and serve as important references for practicing physicians.

Neuroendocrine Tumor Research Foundation has a Doctor Database for help finding a physician specializing in treating neuroendocrine tumors. They also provide a link to a list of multidisciplinary diagnosis and treatment centers on the same web page. lists trials that are related to Neuroendocrine tumor. Click on the link to go to to read descriptions of these studies. Please note: Studies listed on the website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Neuroendocrine Tumor Research Foundation is a non-profit organization to support neuroendocrine tumor (NET) research. Their mission is to accelerate scientific discovery that will help create new and more effective therapies for NETs. Each year they seek and fund basic, translational and clinical research proposals with the potential to further understanding of NETs and accelerate the development of diagnostic and therapeutic interventions for patients. provides oncologist-approved cancer information from the American Society of Clinical Oncology and has information about Neuroendocrine tumor.

Mayo Clinic Web site provides further information on Neuroendocrine tumor.

NET Patient Foundation has an online handbook that aims to serve as a guide to living with neuroendocrine tumors.

Neuroendocrine Tumor Research Foundation provides information about Neuroendocrine tumor.

The American Association of Endocrine Surgeons provides information about Neuroendocrine tumor.

Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.

Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.

Symptoms of neuroendocrine tumours (NETs)

Neuroendocrine tumours (NETs) may not cause any signs or symptoms if they grow slowly and don’t make too much of a certain hormone. Signs and symptoms may appear as the tumour grows or if hormones are released by the tumour (if it is a functional tumour). Other health conditions can cause the same symptoms as NETs.

The signs or symptoms of NETs vary depending on where the tumour develops in the body.

Symptoms of gastrointestinal neuroendocrine tumours (GI NETs)

Gastrointestinal neuroendocrine tumours (GI NETs) can develop in any part of the gastrointestinal tract, including the small or large intestine and stomach. Signs or symptoms of GI NETs may include:

Carcinoid crisis is a severe case of flushing, low blood pressure, difficulty breathing and an irregular heartbeat. It may be triggered by anesthesia, surgery or other treatments. Carcinoid crisis is a serious and possibly life-threatening problem that needs to be treated right away. A drug called octreotide (Sandostatin) can be given to treat and reduce the risk of carcinoid crisis.

Symptoms of lung neuroendocrine tumours (lung NETs)

Lung neuroendocrine tumours (lung NETs) usually develop in the airways (bronchi). Signs or symptoms of lung NETs may include:

Symptoms of pancreatic neuroendocrine tumours (pNETs)

Signs or symptoms of pancreatic neuroendocrine tumours (pNETs) depend mainly on the type of hormone released by the tumour. The signs or symptoms of pNETs include:

About Neuroendocrine Tumors

About Neuroendocrine Tumors What is a neuroendocrine tumor? Most people know very little about neuroendocrine tumors, until they are diagnosed. It is a frightening and stressful experience to learn you have a neuroendocrine tumor (NET).   This site offers information and resources to help patients and caregivers face a neuroendocrine tumor diagnosis. The Neuroendocrine Tumor Research Foundation focuses solely on neuroendocrine tumors. We fund research in search of a cure and we offer educational resources to patients, caregivers, and families living with neuroendocrine tumors.  No matter where you are in your journey, we can help you: Find specialized care or support groups where you live. Learn about the latest treatment approaches Live your healthiest life with NETs

What is a neuroendocrine tumor? A neuroendocrine tumor (NET) is an uncommon cancer type that forms in neuroendocrine cells (Neuroendocrine tumors may also be called islet cell tumors, carcinoid cancer, or carcinoid tumors). NETs can occur almost anywhere in the body, but neuroendocrine tumors most commonly form in the gastrointestinal tract, lung, and pancreas. Neuroendocrine tumors form in neuroendocrine cell Neuroendocrine cells can be found in many different organs. They carry messages from the nervous system to the endocrine system. In response to these messages, the endocrine system makes and releases hormones that control body functions like blood pressure, heart rate, digestion, breathing, and blood sugar. Neuroendocrine cells occur in these organs: Gastrointestinal tract (small intestine, rectum, stomach, colon, esophagus, appendix) Gallbladder Pancreas (islet cells) Thyroid Pituitary glands Kidneys Prostate Ovaries Testicles What do neuroendocrine tumors do? Some neuroendocrine tumors make and release hormones, which can cause a lot of disruptive symptoms. When a NET produces hormones, it is called a “functional” neuroendocrine tumor. When a NET does not produce hormones, it is called a “nonfunctional” neuroendocrine tumor. Functional neuroendocrine tumors produce “peptide” hormones. Peptide is a type of hormone that is made up of amino acids. Some of the peptide hormones NETs produce include: Somatostatin receptors Vasoactive intestinal peptide (VIP) 5-hydroxytryptamine serotonin (5-HT) Gastrin The excess peptide hormones released by a neuroendocrine tumor can cause signs and symptoms. What are the signs and symptoms of neuroendocrine tumors? Signs and symptoms of neuroendocrine tumor vary depending on where the tumor is located. Learn about neuroendocrine tumor sites: Pancreas Gastrointestinal tract Adrenal glands What causes neuroendocrine tumors? Sometimes, something goes wrong inside the neuroendocrine cell and it stops behaving as it should. The neuroendocrine cell grows and divides faster than it should. The excess cells form tumors. We don’t yet know at what point in the neuroendocrine cell lifecycle it becomes cancer. But the Neuroendocrine Tumor Research Foundation has funded millions of dollars in scientific research to answer this question. See what we are learning.

Search for NET specialists Find NET doctors, treatment programs, and support groups near you

Dasari A, Shen C, Halperin D, et al. Trends in the incidence, prevalence, and survival outcomes in patients with neuroendocrine tumors in the United States. JAMA Oncol. 2017;3(10):1335-1342. Singh S, Granberg D, Wolin E, et al. Patient-reported burden of a neuroendocrine tumor (NET) diagnosis: results from the first global survey of patients with NETs. J Glob Oncol. 2016;2(1):43-53.

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What is neuroendocrine cancer?

What are neuroendocrine cells?

Neuroendocrine cells are spread throughout the human body, but are mainly found in the small intestine, pancreas, and lung bronchioles. Neuroendocrine cells act like nerve cells in that they receive messages from the nervous system; they can also release small molecules that circulate throughout the body and work like hormones. High levels of these hormone-like substances can cause symptoms such as flushing or diarrhea.

How does neuroendocrine cancer begin?

Neuroendocrine cancer begins in any of the hormone-producing cells within the neuroendocrine system. There are many different types of neuroendocrine cancer, depending on where the cancer starts growing. These cancers also grow at different rates; some spread to other parts of the body (metastasize) quickly, while others are more slow-growing.

A carcinoid tumor is a type of neuroendocrine tumor that most commonly starts in the lungs or gastrointestinal system (lung bronchioles, stomach, or intestines); carcinoid tumors are most often low grade and slow growing.

Who does neuroendocrine cancer affect?

Neuroendocrine cancers affect men and women about equally, and most are found in people at around the age of 62.