Version July 2025
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What is carcinoid syndrome? —
This is a group of symptoms that can happen when a person has a type of cancer called a "neuroendocrine neoplasm." These are growths that can form in the digestive tract, lungs, or other parts of the body (figure 1 and figure 2). They sometimes then spread to other parts of the body.
Carcinoid syndrome happens with some, but not all, neuroendocrine neoplasms. Most commonly, it happens when cancer that started in the small intestine spreads to the liver. Carcinoid syndrome happens because neuroendocrine neoplasms can make hormones and other substances. When the cancer has spread to the liver, these substances can get into the blood. Then, they can travel around the body and cause symptoms.
What are the symptoms of carcinoid syndrome? —
Symptoms can include:
●Episodes of "flushing" – This is when a person's skin gets red or purple and feels hot. It usually happens on the face, neck, or upper chest. Flushing is the most common symptom of carcinoid syndrome. Episodes usually start suddenly and lasts 30 seconds to 30 minutes. It can happen without warning or be triggered by eating certain foods, drinking alcohol, having a bowel movement, stress, or surgery.
●Spider veins, called "telangiectasias" – These are small, swollen veins that look like purple stripes or spots on the skin. They are usually on the nose, cheek, or upper lip.
●Watery diarrhea that is not bloody
●Wheezing (noisy breathing) or trouble breathing
Sometimes, neuroendocrine neoplasms cause a type of heart disease called "carcinoid heart disease," which affects the heart valves. This doesn't always cause symptoms. When it does, it can cause swelling of the legs or trouble breathing, or make people feel tired.
Is there a test for carcinoid syndrome? —
Yes. Your doctor or nurse will do an exam. They will also order tests to make sure you have carcinoid syndrome and look for neuroendocrine neoplasms in your body.
Tests can include:
●Urine tests – You collect all of the urine you make for 24 hours. This is the test done most often to check whether carcinoid syndrome is the cause of your symptoms.
●Blood tests
●Imaging tests – These create pictures of the inside of the body. They include CT and MRI scans, as well as other tests that involve injecting a special substance into the veins and then using a camera to take images of the body. These tests might be done to find the location of the cancer that is causing your symptoms.
●Endoscopy – This is a procedure that lets the doctor look at the inside of your stomach and first part of your small intestine. The doctor puts a thin tube with a camera and light on the end in your mouth and down into your stomach (figure 3).
●Echocardiogram (also called an "echo") – This uses sound waves to create pictures of your heart as it beats (figure 4).
How is carcinoid syndrome treated? —
Treatment depends on your symptoms, where your cancer is, and how much it has spread in your body.
Some medicines help control your symptoms. They include:
●Medicines that block a neuroendocrine neoplasm from making the hormones or substances that cause symptoms
●Anti-diarrhea medicines
Other treatments try to remove growths or make them smaller, so they can't make as much of the substances that cause problems. They include:
●Surgery to remove all or part of the cancer
●Ablation therapy – This is a procedure to kill cancer cells in the liver. It is not surgery. Doctors can do ablation therapy in different ways. They can kill the cancer cells using extreme cold, heat, microwaves, lasers, or radiation therapy.
●Blocking the cancer's blood supply – Doctors can do a procedure called "embolization" to block off the blood vessel that sends blood to the cancer. This keeps the cancer from growing by "starving" it of its blood supply. Sometimes, this procedure is combined with chemotherapy ("chemoembolization") or radiation ("radioembolization").
●Chemotherapy – These are medicines that kill cancer cells or stop them from growing.
●Targeted therapy – Some medicines work only for cancers with certain characteristics. Your doctor might test your cancer to see if it would respond to these medicines.
●Treatment for carcinoid heart disease – In some cases, this involves surgery to replace a diseased heart valve with a healthy heart valve.
●Lutetium Lu 177-Dotatate (brand name: Lutathera) – This medicine delivers radiation directly into the growth to kill the cancer cells. It is given through a thin tube that goes into your vein, called an "IV."
Is there anything I can do on my own? —
Maybe. If you find that certain things trigger your flushing, try to avoid those things. For example, it might help to avoid eating certain foods or drinking alcohol.
What else should I do? —
Follow all of your doctor's instructions about visits and tests. It's also important to talk to your doctor about any side effects or problems you have during treatment.
Getting treated involves making many choices, such as what treatment to have. Always tell your doctors and nurses how you feel about a treatment. Any time you are offered a treatment, ask:
●What are the benefits of this treatment? Is it likely to help me live longer? Will it reduce or prevent symptoms?
●What are the downsides of this treatment?
●Are there other options besides this treatment?
●What happens if I do not have this treatment?
Patient education: Diarrhea in teens and adults (The Basics)
Patient education: Wheezing in adults (The Basics)
Patient education: Upper endoscopy (The Basics)
Patient education: Echocardiogram (The Basics)
Patient education: Chronic diarrhea in adults (Beyond the Basics)
Patient education: Upper endoscopy (Beyond the Basics)
