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. A carcinoid tumor, which is a type of neuroendocrine tumor, occurs most often in the gastrointestinal tract or the lungs.
Carcinoid syndrome typically occurs in people who have carcinoid tumors that are advanced. 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. Medications may be recommended to relieve your carcinoid syndrome symptoms and make you more comfortable.
The signs and symptoms of carcinoid syndrome depend on which chemicals the carcinoid tumor secretes into your bloodstream.
The most common signs and symptoms include:
Skin flushing. The skin on your face and upper chest feels hot and changes color — ranging from pink to purple. Flushing episodes may last from a few minutes to a few hours or longer.
Flushing may happen for no obvious reason, though sometimes it can be triggered by stress, exercise or drinking alcohol.
Make an appointment with your doctor if you have signs and symptoms that concern you.
Carcinoid syndrome is caused by a carcinoid tumor that secretes serotonin or other chemicals into your bloodstream. Carcinoid tumors occur most often in the gastrointestinal tract, including your stomach, small intestine, appendix, colon and rectum.
Only a small percentage of carcinoid tumors secrete the chemicals that cause carcinoid syndrome. When these tumors do secrete the chemicals, the liver normally neutralizes the 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, it may secrete chemicals that aren't neutralized 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 farther upstream from the liver, which then cannot process and eliminate the chemicals.
Carcinoid tumors in the intestine, on the other hand, secrete the 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.
Having carcinoid syndrome can cause the following complications:
Carcinoid heart disease. Some people with carcinoid syndrome develop carcinoid heart disease. Carcinoid syndrome causes problems with the heart valves, making it difficult for them to function properly. As a result, the heart valves may leak.
Signs and symptoms of carcinoid heart disease include fatigue and shortness of breath. Carcinoid heart disease can eventually lead to heart failure. Surgical repair of damaged heart valves may be an option.
Your doctor will assess your signs and symptoms 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:
A scope or camera to see inside your body. Your doctor may use a long, thin tube equipped with a lens or camera to examine areas inside your body.
An endoscopy, which involves passing a scope down your throat, may help your doctor see inside your gastrointestinal tract. A bronchoscopy, which uses a scope passed down your throat and into your lungs, can help find lung carcinoid tumors. Passing a scope through your rectum (colonoscopy) can help diagnose rectal carcinoid tumors.
Treating carcinoid syndrome involves treating your cancer and may also involve using medications to control your specific signs and symptoms.
Treatments may include:
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:
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:
Find out enough about carcinoid syndrome to make decisions about your care. Ask your doctor questions about your condition. Ask members of your health care team to recommend resources where you can get more information.
Knowing about your condition may enable you to better participate in decisions about your care.
Talk to other people with carcinoid syndrome. Support groups for people with carcinoid syndrome put you in touch with those who have faced the same challenges you are facing.
Ask your doctor about groups in your area. Carcinoid syndrome is rare, though, so you may need to connect with people outside your immediate area or online.
You may start by seeing your family doctor if you have signs and symptoms of carcinoid syndrome. Depending on what your doctor finds, you may be referred to a doctor who specializes in treating cancer (oncologist), a specialist in disorders of the endocrine system (endocrinologist) or a surgeon.
Because appointments can be brief, and because there's often a lot to discuss, it's a good idea to be prepared. Here's some information to help you get ready, and know what to expect from your doctor.
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 other questions as they occur to you.
Your doctor is likely to ask you a number of questions. Being ready to answer them may allow time later to cover other points you want to address. Your doctor may ask:
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