carcinoid syndrome
Meaning of carcinoid syndrome: Carcinoid syndrome causes flushing, diarrhea, and other symptoms when a neuroendocrine tumor releases serotonin into general circulation.
Definition of carcinoid syndrome
Carcinoid syndrome is a combination of symptoms that occurs when a carcinoid tumor, a type of slow-growing neuroendocrine tumor most often arising in the gastrointestinal tract, releases serotonin and other active substances directly into the general circulation. Ordinarily, substances released by these tumors are broken down by the liver before reaching the rest of the body, so carcinoid syndrome typically appears only once the tumor has spread to the liver or otherwise bypasses this normal filtering step.
Symptoms of carcinoid syndrome commonly include flushing of the skin, particularly of the face, watery diarrhea, and episodes of wheezing from airway spasm, along with a rapid heart rate and drops in blood pressure during flushing episodes. Over time, carcinoid syndrome can also affect the heart valves, a complication known as carcinoid heart disease.
Because these symptoms overlap with several other, more common conditions, carcinoid syndrome is typically confirmed through laboratory testing and imaging aimed at identifying the underlying tumor.
Used in a sentence
The patient's episodes of flushing and diarrhea prompted evaluation for carcinoid syndrome.
Good to know
Carcinoid syndrome usually appears only once a carcinoid tumor has spread to the liver, since the liver normally breaks down the tumor's secreted substances before they reach the rest of the body.
Word origin
Where “carcinoid syndrome” comes from
Formed from Greek karkinos, meaning crab, the same root as carcinoma, combined with the suffix -oid, meaning resembling, since these tumors were once thought to resemble carcinomas while behaving more slowly.