Carcinoid
From Wikipedia, the free encyclopedia
| ICD-10 | E34.0 |
|---|---|
| ICD-9 | 259.2 |
| ICD-O: | M8240/3 |
| OMIM | 114900 |
| DiseasesDB | 2040 |
| MedlinePlus | 000347 |
| eMedicine | med/271 |
Carcinoid, also carcinoid tumour and carcinoid tumor, is a slow-growing but often malignant type of neuroendocrine tumour, originating in the cells of the neuroendocrine system. They were first characterized in 1907 by Siegfried Oberndorfer, a German pathologist at the University of Munich, who coined the term karzinoide, or "carcinoma-like", to describe the unique feature of behaving like a benign tumor despite having a malignant appearance microscopically. The recognition of their endocrine-related properties were later described by Gosset and Masson in 1914, and these tumors are now known to arise from the enterochromaffin (EC) and enterochromaffin-like (ECL) cells of the gut.
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[edit] Symptoms
Most carcinoids are asymptomatic through the natural lifetime and are discovered only upon surgery for unrelated reasons; these are called coincidental carcinoids. But all carcinoids are considered to have malignant potential.
About 10 percent of carcinoids secrete excessive levels of a range of hormones, most notably the peptide serotonin (5-HT), causing:
- Flushing
- Diarrhea
- Wheezing
- Abdominal Cramping
- Peripheral Edema
This constellation of symptoms is called carcinoid syndrome or (if acute) carcinoid crisis. Occasionally, haemorrhage or the effects of tumor bulk are the presenting symptoms. The most common originating sites of carcinoid is the small bowel, particularly the ileum; carcinoid tumors are the most common malignancy of the appendix, and ovarian origin, though reported, is rare.
[edit] Treatment
Surgery, if feasible, is the only curative therapy. If the tumour has metastasized (most commonly, to the liver), the tumour may be ineligible for surgery (unresectable), though there are many promising treatment modalities, such as radiolabeled Octreotide, that are very effective in arresting the growth of the tumors and prolonging survival in patients with liver metastases.
Chemotherapy is of little benefit and is generally not indicated. Octreotide (a somatostatin analogue) may decrease the secretory activity of the carcinoid.
Carcinoid tumours are the most common malignant tumor of the appendix, but they are most commonly associated with the small intestine, but they are also found in the rectum and stomach. They are known to grow in the liver, but this finding is usually a manifestation of metastatic disease from a primary carcinoid occurring elsewhere in the body. They have a very slow growth rate compared to most malignant tumours.
[edit] GOBLET CELL CARCINOID
This is considered to be a hybrid between an exocrine and endocrine tumor derived from crypt cells of the appendix. Histologically, it forms clusters of goblet cells containing mucin with a minor admixture of Paneth cells and endocrine cells. The growth pattern is distinctive: typically producing a concentric band of tumor nests interspersed among the muscle and stroma of the appendiceal wall extending up the shaft of the appendix. This makes the lesion difficult to suspect grossly and difficult to measure. Small tumor nests may be camouflaged amongst the muscle or in periappendiceal fat; cytokeratin preparations best demonstrate the tumor cells; mucin stains are also helpful in identifying them. They behave in a more aggressive manner than do classical appendiceal carcinoids. Spread is usually to regional lymph nodes, peritoneum, and particularly the ovary. They do not produce sufficient hormonal substances to cause the carcinoid or other endocrine syndromes. In fact, they more closely resemble exocrine than endocrine tumors. The term 'crypt cell carcinoma' has been used for them, and though perhaps more accurate than considering them carcinoids, has not been a successful competitor. The ICD-O code for goblet cell carcinoid is 8243/3.
