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Related to carcinoid: carcinoid syndrome, Carcinoid tumor


1. a yellow circumscribed tumor of the gastrointestinal tract or bronchus formed from chromaffin cells. See also carcinoid syndrome.
carcinoid syndrome a symptom complex associated with carcinoid tumors (argentaffinomas), marked by attacks of severe cyanotic flushing of the skin lasting from minutes to days and by watery diarrhea, bronchoconstrictive attacks, sudden drops in blood pressure, edema, and ascites. Symptoms are caused by serotonin, prostaglandins, and other biologically active substances secreted by the tumor.

The specific symptoms associated with this disorder depend upon the site of the primary tumor; tumors are found most commonly in the appendix and the terminal third of the ileum but can also be in the bronchi, ovaries, testes, and anywhere along the entire length of the alimentary tract. The full set of carcinoid symptoms are manifested only when the liver is involved.

Diagnosis of the condition is established by a 24-hour urine test for 5-hydroxyindoleacetic acid (5-HIAA), the end product of the breakdown of tryptophan to serotonin. Patients with carcinoid syndrome may have very high levels of 5-HIAA, 100 to 500 mg in 24 hours.

Carcinoid tumors are not always benign and should be approached as if they were malignant growths. Surgical excision of the tumor and any associated mesenteric nodes is the treatment of choice. Chemotherapy can be used with metastatic disease, and other drugs are prescribed as indicated to manage the hypotension, diarrhea, flushing, and other symptoms. Efforts are made to improve nutrition and to avoid serotonin-containing foods, such as walnuts and bananas, which are known to precipitate an attack and make accurate diagnosis difficult.

car·ci·noid tu·mor

a usually small, slow-growing neoplasm composed of islands of rounded, oxyphilic, or spindle-shaped cells of medium size, with moderately small vesicular nuclei, and covered by intact mucosa with a yellow cut surface; neoplastic cells are frequently palisaded at the periphery of the small groups, and the latter have a tendency to infiltrate surrounding tissue. Such neoplasms occur anywhere in the gastrointestinal tract (and in the lungs and other sites), with approximately 90% in the appendix and the remainder chiefly in the ileum, but also in the stomach, other parts of the small intestine, the colon, and the rectum; those of the appendix and small tumors seldom metastasize, but reported incidences of metastases from other primary sites and from tumors exceeding 2.0 cm in diameter vary from 25-75%; lymph nodes in the abdomen and the liver may be conspicuously involved, but metastases above the diaphragm are rare. About 1% of cases are associated with the carcinoid syndrome, usually after the portal circulation is bypassed as in cases involving liver metastases.
See also: carcinoid syndrome.


/car·ci·noid/ (kahr´sĭ-noid) a yellow circumscribed tumor arising from enterochromaffin cells, usually in the gastrointestinal tract; the term is sometimes used to refer specifically to the gastrointestinal tumor (argentaffinoma) .


A small, slow-growing, benign or malignant tumor, found usually in the gastrointestinal tract, that is composed of islands of rounded cells and secretes serotonin.


Etymology: Gk, karkinos + eidos, form
a small yellow tumor derived from argentaffin cells in the GI mucosa that secrete serotonin and other catecholamines. Carcinoid tumors spread slowly locally but may metastasize widely. Also called argentaffinoma, Kulchitsky-cell carcinoma. See also argentaffin cell, carcinoid syndrome.
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Carcinoid tumor


A well-differentiated tumour of neuroendocrine-neural crest origin, which has paracrine activity. 85% of carcinoid tumours are located in the GI tract (appendix, liver, ileum, stomach, colon, rectum),10% in the lungs and bronchi, and the rest in the breast, kidney, ovary, prostate, skin, thymus, and elsewhere.

Clinical findings
Flushing, tachycardia, facial and periorobital swelling, low blood pressure, abdominal pain, weight loss, diarrhoea.
Appendiceal carcinoids are clinically benign; liver carcinoids are usually functionally malignant, as they release large amounts of vasoactive amines (e.g., serotonin) into the circulation.

Increased serotonin, 5-HIAA in serum, urine.

Carcinoids basic classification
Microcarcinoid Tumourlet < 0.5 cm in diameter.
Carcinoid Benign Usually measure > 0.5 cm; either invades muscularis mucosae or is macroscopically visible, but confined to mucosa or submucosa and not angioinvasive.
Borderline carcinoid Either angioinvasive, but measures < 1 cm and is confined to mucosa/submucosa or 1–2 cm, no angioinvasion and limited to the mucosa/submucosa.
Mucinous/goblet cell carcinoid Aggressive; possibly same as agyrophilic adenocarcinoma.
Atypical carcinoid Carcinoid + necrosis OR mitoses > 2/10hpf OR cytological atypia.
Malignant carcinoid Carcinoid + functional tumour OR > 1 cm + angioinvasion OR invades muscularis propria.

Note: The term neuroendocrine tumour is increasingly preferred.


a tumor of the gastrointestinal tract formed from the endocrine (argentaffin) cells of the mucosal lining of a variety of organs including the stomach and intestine. In dogs they occur in the duodenum, colon and rectum, producing the carcinoid syndrome. Called also argentaffinoma, argentaffin tumor.

goblet-cell carcinoid
a rare tumor recorded in a dog; more common in human appendix; has characterisitics of carcinoid and adenocarcinoma. Called also adenocarcinoid.
hepatic carcinoid
a rare tumor originating from neuroectodermal tissue in the liver.

Patient discussion about carcinoid

Q. what is carcinoid tumors? I had my appendix removed and the doctor came in the room very shocked and said it was full of carcinoid tumors. Im scared to get them somewhere else.

A. ya I have pain all the time but the doctors wont give me anything cuz im so young they don't want me hooked on anything. thank you sooo much for being so kind.

More discussions about carcinoid
References in periodicals archive ?
Also, in four patients with paraganglioma, pheochromocytoma, parathyroid adenoma, and carcinoid tumors, who were monitored throughout their treatment course, CgA dropped sharply in the post-treatment phase within days, weeks or months, depending on the tumor.
2,4) It has been shown that mASH1 antibody (nuclear staining), which cross-reacts with hASH1, can help discriminate carcinoids from HGNECs in various neoplastic sites.
When abdominal carcinoid tumors are suspected, the preferred imaging technique is CT, which typically shows mucosal thickening, a submucosal mass, or luminal narrowing.
Typical carcinoid grows in ribbons, nests, and festoons of relatively small to medium cells showing an intermediate nuclear-to-cytoplasmic ratio and round nuclei with delicate, salt-and-pepper nuclear chromatin distribution.
Carcinoid tumours are slow-growing tumours, derived from enterochromaffin (EC) cells located in the crypts of LieberkA1/4hn, a part of neuroendocrine system.
7%) had Meckels diverticulitis, and one each case were diagnosed as adenocarcinoma and carcinoid tumor.
Even though available data clearly demonstrates differing trends in lung cancer incidence the rates for squamous cell Non- small cell Small cell undifferentiated and Carcinoid carcinoma among men peaked in 2008 but decreased in the year 2009.
Professor Makin said several improvements had been introduced recently and much more was known about carcinoid tumours which were very rare.
commercializing telotristat etiprate outside of North America and Japan for the treatment of carcinoid syndrome.
8] Carcinoids may occasionally present with symptoms of carcinoid syndrome (flushing, tachycardia, and diarrhea).
A carcinoid tumour of the testis can be divided into 3 groups: primary carcinoid tumour, metastasis from a different location, and carcinoid tumour arising in a testicular teratoma.
Due to the patient's poor condition, intolerance to steroidogenesis inhibitors, and in order to avoid empiric adrenalectomy, a bronchoscopy was preformed and identified a small submucosal bronchopulmonary carcinoid tumor (BPC).