Carcinoid syndrome is a rare condition that occurs in people with carcinoid tumors. Only about 10% of the people with a carcinoid tumor will develop carcinoid syndrome.
These tumors are slow-growing cancers that typically develop in the gastrointestinal tract, such as in the appendix, small intestine, or rectum, but can also occur in the lungs. The exact cause of carcinoid tumors is not known, but certain factors may increase the risk of developing them.
Carcinoid tumors are more common in older adults, with most cases diagnosed in people over the age of 60. They are also more common in women than in men. Some inherited conditions, such as multiple endocrine neoplasia type 1 (MEN1) and neurofibromatosis type 1 (NF1) may also increase the risk of developing carcinoid tumors.
Smoking and exposure to certain chemicals have also been linked to an increased risk of developing carcinoid tumors. People who have a history of smoking or have been exposed to certain chemicals, such as those used in the rubber and dye industries, may have a higher risk of developing the condition.
It’s important to note that not all people with carcinoid tumors may develop carcinoid syndrome and some people with the syndrome may not have any visible tumors. A definitive diagnosis of carcinoid syndrome can only be made once a carcinoid tumor has been identified and the typical symptoms are present.