Definition

Noun: A carcinoid is a type of slow-growing neuroendocrine tumor. It most commonly arises from cells in the lining (mucosa) of the gastrointestinal tract or, less frequently, the lungs. While often benign, it can be malignant. These tumors are notable for their potential to secrete excessive amounts of hormones and chemical messengers, most characteristically serotonin.

Usage and Examples

• As a subject:

  • The carcinoid was discovered incidentally during a routine colonoscopy.
  • A pulmonary carcinoid can sometimes cause a persistent cough.

• As an object:

  • The surgeon successfully removed the carcinoid.
  • Biopsy results confirmed the presence of a carcinoid.

• With modifiers:

  • The patient was diagnosed with a benign carcinoid.
  • Management of a malignant carcinoid often requires a multidisciplinary approach.

Advanced Usage and Medical Context

• Carcinoid syndrome: A specific set of symptoms (e.g., flushing, diarrhea, wheezing) caused when a carcinoid tumor, typically one that has spread to the liver, releases large amounts of serotonin and other substances into the bloodstream.

  • The onset of severe flushing led doctors to suspect carcinoid syndrome.

• Carcinoid tumor/carcinoid neoplasm: These are fuller, more formal terms equivalent to "carcinoid."

  • The pathology report classified the growth as a carcinoid tumor.

Variants and Related Words

• Carcinoidosis (noun): A rare condition involving multiple or widespread carcinoid tumors.
• Neuroendocrine tumor (NET) (noun): The broader category of tumors to which carcinoids belong. "Carcinoid" is often considered a traditional term for certain NETs.

Synonyms and Near Synonyms

• Neuroendocrine tumor (NET): A more modern and general term.
• Argentaffinoma (noun, historical): An older term based on the tumor's staining properties, now largely superseded by "carcinoid" or "NET."

Important Notes on Meaning

While the reference definition states it is a "small tumor," in clinical practice, carcinoids can vary in size. Their defining features are their origin (neuroendocrine cells, often in GI or lung mucosa), slow growth, and secretory potential. The association with excessive serotonin secretion is a key characteristic, especially when symptoms of carcinoid syndrome are present.

Noun

1. a small tumor (benign or malignant) arising from the mucosa of the gastrointestinal tract; usually associated with excessive secretion of serotonin