What does carcinoid mean?
A carcinoid is a small, typically slow-growing tumour arising from neuroendocrine cells, most commonly found in the appendix, small intestine, rectum, or bronchial passages of the lung. The name, meaning 'cancer-like', was coined in the late nineteenth century because early pathologists judged these growths to be less aggressive than true carcinomas. Many carcinoids cause no symptoms for years and are discovered incidentally during surgery or imaging; others secrete biologically active substances such as serotonin, producing flushing, diarrhoea, and sometimes heart-valve damage — a cluster of effects called carcinoid syndrome. Treatment usually involves surgical removal, supplemented where necessary by hormonal therapies. The term remains standard in pathology, though contemporary oncology increasingly favours 'neuroendocrine tumour'. Knowing this word helps readers interpret medical reports and understand a category of tumours whose behaviour sits between benign and overtly malignant disease.
nounA carcinoid is a small, slow-growing neuroendocrine tumour that arises most often in the gastrointestinal tract or bronchial system, capable of secreting hormonally active substances such as serotonin.
- A small, slow-growing neuroendocrine tumour, most often arising in the gastrointestinal tract or lungs, which may secrete hormones such as serotonin.
- Such a tumour when considered as part of the disease process leading to carcinoid syndrome (flushing, diarrhoea, and heart-valve changes caused by excess serotonin).
"The biopsy revealed a carcinoid in the appendix, prompting the surgeon to recommend a wider resection."
"An incidental carcinoid was found at the tip of the appendix during routine surgery."
"Patients with metastatic carcinoid disease may develop flushing and diarrhoea known collectively as carcinoid syndrome."
Regular plural; used when referring to multiple tumours, either in one patient or across patients.
"Screening revealed two separate carcinoids, one ileal and one pulmonary."
Its name literally means 'cancer-like' — a hedge coined by German pathologists who couldn't decide whether these odd little tumours deserved the word 'cancer' at all.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of carcinoid
The word carcinoid was introduced in German medical literature in the late nineteenth century, combining the Greek-derived element carcino- (from karkinos, 'crab', the ancient root of 'cancer') with the suffix -oid, meaning 'resembling'. It literally denotes something resembling carcinoma without fully being one. The same Greek root underlies carcinoma, carcinogen, and ultimately the English word cancer via Latin.
Related word forms
How carcinoid is actually used
Strictly a medical term; used almost exclusively by clinicians and pathologists. In modern practice many authorities prefer the broader term 'neuroendocrine tumour' (NET), since 'carcinoid' derives from an outdated belief that these growths were merely benign imitations of cancer. Plural is 'carcinoids'; the adjective form ('carcinoid syndrome') functions attributively rather than being a separate derivative.
Easily confused with carcinoid
A carcinoma is a malignant tumour of epithelial cells, whereas a carcinoid is a typically slower-growing tumour of neuroendocrine cells — the shared root means 'crab-like cancer', but they are distinct diseases.