Carcinoid Syndrome

1 What is Carcinoid Syndrome?

Carcinoid syndrome refers to a set of signs and symptoms that occur in patients with a rare cancerous tumor called a carcinoid tumor.

Majority of carcinoid tumors are found in the gastrointestinal tract or lungs.

Mild carcinoid tumor can remain asymptomatic, and the symptoms may not surface until the cancer has reached advanced stage, thus making its cure more difficult.

Treating the cause, that is carcinoid tumor, is the mainstay of the treatment of carcinoid syndrome.

2 Symptoms

Signs and symptoms of carcinoid syndrome include:

Skin flushing

Feeling of warmth on the face and upper chest with skin color changing from pink to purple.

Flushing lasts for a few minutes to few hours and may be triggered by stress, exercise or alcohol while it may sometime occur without any obvious reason.

  • Facial skin lesions
  • Purplish areas of spiderlike veins may appear on the nose and upper lip
  • Frequent watery diarrhea
  • Asthma-like signs and symptoms, such as wheezing and difficulty breathing
  • Palpitations

When to see a doctor?

Talk to your doctor if you experience any of the signs and symptoms.

3 Causes

Carcinoid tumors that secrete “too much” serotonin or several other chemicals into the bloodstream are the major cause of Carcinoid syndrome.

Carcinoid tumors are commonly found in your gastrointestinal tract, including

  • your stomach,
  • small intestine,
  • appendix,
  • colon and rectum,
  • in your lungs.

Most carcinoid tumors do not produce carcinoid syndromes and the symptoms are observed only when the tumor has reached advanced stage.

Advanced tumor secretes a very large quantity of chemicals which the liver cannot neutralize.

In case of mild carcinoid tumor, the secretions are little and your liver neutralizes them.

However, not all the cases of carcinoid syndrome are due to advanced tumors.

The exact cause of carcinoid tumors is still not known.

4 Making a Diagnosis

Making a diagnosis of carcinoid syndrome is done by performing several tests.

Talk to your doctor if experience any of the signs and symptoms. Your doctor may refer you to:

  • Oncologist- a cancer specialist
  • Endocrinologist: a doctor who specializes in the disorders of endocrine system
  • A surgeon

How to prepare yourself for the visit?

Getting prepared for the visit can optimize the therapy and help make the visit more fruitful. List out all the symptoms.

Write down your key medical information. Write down the names of all your medications, vitamins or supplements.

Ask a friend or a family member to accompany you during the visit.

Make a list of the questions to ask your doctor

Some typical questions can be:

  • Do these symptoms indicate a carcinoid tumor? If yes, what’s the stage?
  • Has my cancer affected other body parts?
  • What are the tests that I need?
  • What are my treatment options and side effects of each option?
  • Can my condition be cured?
  • How will treatment affect my daily routine?
  • What about the risk for my family members?

What your doctor wants to know?

A clear talk with your doctor can optimize the therapy and improve the outcomes. Prepare yourself to answer some essential questions from your doctor. Your doctor might ask you typical questions like:

  • When did the symptoms start appearing and how severe are they?
  • Does any factor improve or aggravate your symptoms?
  • Has anyone in your family been diagnosed with cancer of any kind?

Your doctor examines and evaluated your signs and symptoms to determine the possible causes. In case no obvious causes are found, your doctor may suspect carcinoid syndrome.

Further testing to confirm carcinoid syndrome include:

Urine test

Your urine may be tested to look for the chemicals that form after breakdown of serotonin.

Elevated level of such chemicals could signal excess serotonin production in your body.

Remember serotonin is a common secretion of carcinoid tumors.

Blood test

High blood levels of the protein chromogranin A, which is released by some carcinoid tumors, could signal carcinoid syndrome.

Imaging tests

Imaging techniques such as CT, MRI or nuclear medicine scans can be used to identify and locate primary carcinoid tumor and to determine if it has spread.

Since abdominal carcinoid tumors are commonly found, your doctor may start with abdominal CT scan.

5 Treatment

Treatment of carcinoid syndrome aims to treat the causative tumor and control the signs and symptoms by using medications. The choice of treatment option depends upon the size and location of the tumor.

Treatments include:


An entire or a portion your cancer can be surgically removed. If the cancer has spread extensively making surgery impossible, your doctor can recommend other treatments that shrink the tumor.

Medications to reduce amount of secretions

Injectable medications, such as octreotide and lanreotide can reduce the signs and symptoms, including skin flushing and diarrhea.

These drugs don’t reduce the size of tumor but may slow its growth. Common side effects include abdominal pain and bloating.

Biological therapy

This treatment activates your immune system against the tumor cells. Injections of a drug called interferon alfa can slow down the tumor growth.

Side effects include fatigue and flu-like symptoms.

Cutting blood supply to liver tumors

This process is called hepatic artery embolization. A catheter is inserted near your groin which passes an emboli through the artery that supplies your liver (hepatic artery).

The emboli reduces blood supply to cancer cells. This process is risky and is not widely available. Consult with your doctor to determine risk to benefit ratio.

Killing cancer cells by applying heat or cold

Radiofrequency ablation kills the cancer cells by applying heat obtained from various sources. Likewise, cryotherapy works in the same line but uses freezing temperature to destroy the tumor.


It uses chemicals to kill or shrink the tumor. The side effects of chemotherapy are specific to the particular drug.

6 Lifestyle and Coping

Various self-care measures can help you better cope with the symptoms of carcinoid syndrome.

These measures do not actually treat the condition but often make the symptoms more manageable.

Consult your doctor before applying any coping techniques.

These suggestions can be beneficial for you: 

Stay away from the triggers of skin flushing

Certain triggers such as alcohol, large meals or stress can cause skin flushing. Keep track of what causes skin flushing and avoid them as far as possible.

Consider taking a multivitamin supplement

Chronic diarrhea may cause deficiency of micronutrients. Talk to your doctor if multivitamin supplements are beneficial.

Join a support group in your community or online, if available

Consult your doctor to know more about a support group for people with carcinoid syndrome.

Update and expand your knowledge

Update and expand your knowledge about your condition through authentic health information sources.

Live a healthy life

Increase your intake of fruits and vegetables. Stay physically active.

Manage your stress.

7 Risk and Complications

There are several complications associated with carcinoid syndrome, which include:

It is a condition in which your heart valves are thickened, causing abnormal valve functions which may lead to heart failure.

The signs and symptoms of carcinoid heart disease include fatigue and shortness of breath during physical activity.

Medications and surgery may be recommended by your doctor to alleviate the condition.

  • Bowel obstruction

Your bowel may be obstructed by the carcinoid tumors that spread to the lymph nodes beside your small intestine.

The signs and symptoms of a bowel obstruction include severe, cramping abdominal pain and vomiting.

You may require surgery to correct bowel obstruction.

  • Carcinoid crisis

It is a life-threatening condition that occurs when your carcinoid tumor releases of an enormous amount of biologically active compounds.

The symptoms include

It occurs most commonly when your carcinoid tumor is exposed to triggers like an anesthetic medication.

Therefore, your doctor can recommend certain medication before surgery to reduce the risk of carcinoid crisis.

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