Carcinoid syndrome occurs when a rare cancerous tumor called a carcinoid tumor secretes certain chemicals into your bloodstream, causing a variety of signs and symptoms. Carcinoid tumors occur most commonly in the gastrointestinal tract or lungs.
Because carcinoid tumors generally grow slowly, you typically wouldn't experience carcinoid syndrome until the tumors are quite advanced. You might discover you have carcinoid cancer through a test for an unrelated disease or condition.
Treatment for carcinoid syndrome usually involves treating the cancer. However, because most carcinoid tumors don't cause carcinoid syndrome until they're advanced, a cure may not be possible. In those cases, medications may relieve your symptoms of carcinoid syndrome and make you more comfortable.
The signs and symptoms of carcinoid syndrome depend on which chemicals your carcinoid tumor secretes into your bloodstream. They may be triggered by alcohol, stress and heavy exercise. The most common signs and symptoms of carcinoid syndrome include:
Keep in mind that many of these signs and symptoms are more likely the result of a condition other than carcinoid syndrome. Experiencing these symptoms doesn't necessarily mean you have a carcinoid tumor.
When to see a doctor
Carcinoid syndrome is caused by a carcinoid tumor that secretes serotonin or other chemicals into your bloodstream. Carcinoid tumors occur most commonly in your gastrointestinal tract, including your stomach, small intestine, appendix, colon and rectum, or in your lungs.
Only a small percentage of carcinoid tumors secrete the chemicals that cause carcinoid syndrome. In most cases, the liver effectively degrades those chemicals before they have a chance to travel through your body and cause symptoms. However, when an advanced tumor spreads (metastasizes) to the liver itself, these tumors may secrete chemicals, which are not degraded before reaching the bloodstream. Most people who experience carcinoid syndrome have an advanced cancer that has spread to the liver.
Some carcinoid tumors don't have to be advanced to cause carcinoid syndrome. For instance, carcinoid lung tumors that secrete chemicals into the blood do so much farther upstream from the liver — not directly into the liver, where the chemicals are processed and eliminated. Carcinoid tumors in the intestine, on the other hand, secrete their chemicals into blood that must first pass through the liver before reaching the rest of the body. The liver usually neutralizes the chemicals before they can affect the rest of the body.
What causes carcinoid tumors is unclear.
Only people with carcinoid tumors are at risk of carcinoid syndrome. People with carcinoid tumors are more likely to experience carcinoid syndrome if they have a gastrointestinal carcinoid tumor, especially if the tumor has spread (metastasized) to the liver.
Having carcinoid syndrome can cause the following complications:
Preparing for your appointment
You may start by seeing your family doctor or a general practitioner if you have signs and symptoms of carcinoid syndrome. Based on what your doctor finds, you may be referred to a doctor who specializes in treating cancer (oncologist), disorders of the endocrine system (endocrinologist) or a surgeon.
Because appointments can be brief, and because there's often a lot of ground to cover, it's a good idea to be well prepared for your appointment. Here's some information to help you get ready, and what to expect from your doctor.
What you can do
Your time with your doctor is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For carcinoid syndrome, some basic questions to ask your doctor include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.
What to expect from your doctor
Tests and diagnosis
Your doctor will assess your signs and symptoms in order to rule out other causes of skin flushing and diarrhea. If no other causes are found, your doctor may suspect carcinoid syndrome. To confirm a diagnosis, your doctor may recommend further tests, including:
Treatments and drugs
Treating carcinoid syndrome involves treating your cancer and may also involve using medications to control your specific signs and symptoms.
Treatments may include:
The prognosis for people living with carcinoid cancer varies widely, depending on the extent of tumor spread and whether carcinoid syndrome has developed. As cancer research continues, doctors are finding new ways to treat advanced cancers, which may improve survival.
Lifestyle and home remedies
Talk to your doctor about self-care measures that may improve your signs and symptoms. Self-care measures can't replace treatment, but they may complement it. Ask your doctor if you should:
Coping and support
You may be relieved to finally find an answer to what's been causing your signs and symptoms, but a diagnosis of a rare disease such as carcinoid syndrome can be stressful. As you develop your way of coping with a cancer diagnosis, talk with your health care team about how you feel and consider trying to:
Last Updated: 2010-05-01
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