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.
Carcinoid syndrome occurs when carcinoid tumors overproduce hormones and other substances that normally circulate throughout your body. One of the most important substances that is overproduced is serotonin – one of the body’s natural chemical messengers. When excess seretonin reaches tissues in the gastrointestinal tract, the lungs, or the skin, it causes the symptoms of carcinoid syndrome.
Carcinoid tumors often do not produce noticeable symptoms until they spread to the liver. That’s because most of the blood circulation from the gastrointestinal tract must pass through the liver before it reaches the rest of the body. The liver has strong enzymes that break down and neutralize most of the excess serotonin and other substances produced by the carcinoid tumors, preventing them from reaching tissues where they can cause symptoms. When carcinoid tumors metastasize to the liver, the substances they overproduce can more easily reach your bloodstream, and reach tissues where they can cause symptoms. Symptoms may include (starting with the most common and going to the least):
- dry flushing
- nocturnal diarrhea
- heart valvular lesions
- telangiectasia (reddish spots or veins that appear)
- peripheral edema (swelling of the legs or arms)
- cyanosis (bluish skin spots)
- pallagra (skin rash)
It is important that you keep your healthcare team informed if any new symptoms occur, so they can help you better manage your disease.
The diagnosis of carcinoid syndrome if often difficult in it’s early stages. Most of the symptoms are common and are similar to diseases that are not so rare. However the first two symptoms listed above, dry flushing (flushing without sweating) and nighttime only diarrhea, might suggest carcinoid syndrome rather than another more common condition. There are several tests that our board certified physicians can use to diagnose carcinoid syndrome and to monitor it once it had been diagnosed. It’s important to be monitored regularly for changes in your symptoms or test results. Regular doctor visits will also help you get the best possible outcome.