Carcinoid tumor and related
neuroendocrine tumors are slow growing tumors
found mostly in the gastrointestinal system, but can be in other
parts of the body such as the pancreas and the lung. Since most of
these grow very slowly, compared to other cancers, it usually takes
many years before they become sizable or cause symptoms.
tumors can produce an excess of hormone-like substances, such
as serotonin, bradykinin, histamine, and prostaglandins.
Excess levels of these substances can sometimes result in a
diverse set of symptoms called carcinoid syndrome.
carcinoid tumors occur in the digestive tract or
pancreas, the substances they produce are released
into a blood vessel that flows directly to the liver
(portal vein), where enzymes destroy them.
Therefore, carcinoid tumors that originate in the
digestive tract generally do not produce symptoms
unless the tumors have spread to the liver.
39% small intestine
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