carcinoid tumor segment under the microscope
carcinoid tumor segment under the microscope
carcinoid tumor segment under the microscope

Carcinoid Tumor

Carcinoid tumor is a rare type of tumor that usually grows slowly.

Carcinoid tumors are cancerous, but have been called cancer in slow motion, because if you have a carcinoid tumor, you may have it for many years and never know it. In rare cases, usually after a carcinoid tumor has spread, it can cause symptoms called carcinoid syndrome.

Facts about carcinoid tumor

Fewer than 10% of people with carcinoid tumors have or develop symptoms. That statistic may vary, based on the location of the tumor. Because carcinoid tumors grow so slowly, they are usually not diagnosed until age 55 to 65. Gastrointestinal carcinoid tumors are more common among black people than white people. Black men have a higher risk than black women. Among white people, men and women have the same risk.

Experts don't know what causes carcinoid tumors. If you have a rare disease that runs in families called multiple endocrine neoplasia type 1 (MEN1), you have a higher risk of getting a carcinoid tumor. You may also increase your risk of getting this tumor by smoking.

Carcinoid tumors can grow anywhere in your body where hormone-producing cells are present. Hormones are your body's chemical messengers that travel through your blood. Most of carcinoid tumors form in the digestive (gastrointestinal) tract.

Types of carcinoid tumors

Here are the areas of the body where carcinoid tumors are usually found:

  • Small intestine

  • Appendix

  • Rectum

  • Lungs

  • Colon

  • Stomach

  • Pancreas

  • Liver

Carcinoid tumors behave differently depending on how quickly they grow, if they spread to other areas of your body, and if they make too much hormone. Types of carcinoid tumors include:

  • Slow-growing tumors. These tumors are the most common type. They usually remain small, under about an inch wide. They don’t grow quickly or spread to other areas of the body.

  • Faster-growing tumors. These tumors may grow more rapidly, grow larger, and spread.

  • Hormone-secreting tumors. These functioning carcinoid tumors produce hormones including serotonin. The effect of serotonin and other hormones causes the symptoms known as carcinoid syndrome.


Symptoms of carcinoid tumor depend on where the tumor is growing and whether the tumor is producing hormones and other chemicals (carcinoid syndrome). If you have a tumor that is not causing carcinoid syndrome, you may have no symptoms at all and your tumor may be discovered during a routine exam.

Symptoms of tumors not causing carcinoid syndrome may include:

  • Abdominal pain or pressure

  • Change in bowel habits

  • Blood in a bowel movement

  • Chest pain

  • Cough

  • Wheezing

  • Blood-tinged sputum

  • Weight loss

Symptoms caused by carcinoid syndrome may be triggered by exercise, stress, and some foods or drinks, such as alcohol (especially red wine), chocolate, and certain cheeses. These are common symptoms:

  • Flushing of your face

  • Diarrhea

  • Asthma

  • Fainting

  • Heart palpitations


Diagnosing a small carcinoid tumor that’s not causing carcinoid syndrome symptoms is difficult. These tumors are usually found when doing surgery or in an exam for another condition. For example, some carcinoid tumors are found when a healthcare provider removes an appendix for appendicitis.

These tests may be used to help diagnose carcinoid tumor:

  • X-rays and scans. Chest X-ray, computed tomography (CT) scan, and magnetic resonance imaging (MRI) scan are all useful in diagnosis.

  • OctreoScan. This is a special type of scan that is most often used to find carcinoid tumors. This scan is taken after injection of a radioactive substance that is picked up by carcinoid tumor cells.

  • Exam and biopsy. A surgical procedure to test a sample of tissue from the carcinoid tumor and look at it under a microscope is important for diagnosis. Sometimes this is done by using a flexible scope to look inside your body. This procedure is called endoscopy. If a tumor is found, your healthcare provider may take a sample of the tissue for biopsy.

  • Urine test. If you have a carcinoid tumor that is making too much hormone, it may show up as a type of acid in your urine called 5-HIAA (5-hydroxy indole acetic acid). This is a waste product of serotonin.

  • Blood test. A blood test may show an increased level of the hormone serotonin or high levels of chromogranin A (CgA). This is another substance made by most carcinoid tumors.


The best treatment for small carcinoid tumors that have not spread is surgery. Surgery for these tumors can cure them. Once a tumor has spread or become too big to remove, other treatments may still work well. Here are some treatments that may be used:

  • Partial surgery. If a tumor is too big to take out completely, surgery may be used to remove part of it so that other treatments may work better.

  • Chemotherapy. Medicines that fight carcinoid tumor cells may be given into your bloodstream or taken by mouth. Usually it is best to give several of these medicines in combination.

  • Octreotide. This is a medicine that is given by injection. This medicine helps control the symptoms of carcinoid tumor and may also block or reverse tumor growth.

  • Liver treatment. If a carcinoid tumor has spread into your liver, chemotherapy medicines may be injected into your liver, or small pellets may be injected that block blood flow to the tumor cells.

You may also want to get a second opinion before starting treatment. Some insurance companies need one for certain cancer diagnoses. In addition to providing more information, a second opinion can also provide peace of mind regarding your treatment decisions. 


There is no way to prevent the growth of a carcinoid tumor. One risk factor that you can control is smoking. You may be able to lower your risk for carcinoid tumor by not smoking. Treating carcinoid tumor may help you prevent the symptoms of carcinoid syndrome.

Managing carcinoid tumor

In addition to following all your healthcare providers' instructions, taking your medicines, and keeping all your appointments, you can help manage carcinoid tumor by learning as much as you can about the disease and taking an active role in your treatment. Here are some other management suggestions:

  • Make sure you follow a nutritious, high-protein diet.

  • Avoid alcohol and foods that trigger carcinoid symptoms.

  • Avoid stress as much as possible.

  • Ask your healthcare provider about the medicines you take. Some medicines, such as decongestants, asthma inhalers, and antidepressants, may trigger or make carcinoid symptoms worse.

  • Join a support group to learn more about carcinoid tumors and share your feeling with others.

  • Try mind-body exercises like yoga or tai chi to help reduce anxiety and stress.

  • Try other ways of managing emotional stress: guided imagery, meditation, music therapy, and journaling.

  • Before appointments, write down your questions and bring them with you. For support during your appointments, bring a family member or close friend with you. 

Home remedies

Home remedies will not cure carcinoid tumors. Vitamin supplements may be helpful. Mineral supplements, such as potassium, magnesium, and calcium may also help. Freshly ground nutmeg will sometimes help control diarrhea. Always let your healthcare provider know about any home remedies you want to try.

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