Where carcinoid tumors develop? What are carcinoid tumors? You will find answers to these questions by reading this article.
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Carcinoid tumors may appear where there are cells that produce hormones - in principle, throughout the body. Larger carcinoid tumors (65%) develop in the gastrointestinal tract. In most cases, the carcinoid tumor develops in a small intestine, appendix and rectum. Less frequently, carcinoid tumors develop in the stomach and colon; Pancreas, gallbladder and liver in the smallest degree are subject to carcinoid tumor (despite the fact that the carcinoid tumor in the liver usually gives metastases).
Approximately 25% of carcinoid tumors affect the respiratory tract and light. The remaining 10% can be detected anywhere. In some cases, doctors cannot determine the localization of the carcinoid tumor, despite the fact that they are known for the symptoms of carcinoid syndrome.
Summarizing the foregoing, we present the following classification of carcinoid tumors, depending on their location:
- carcinoid tumors of the small intestine;
- Appendicular carcinoid tumors;
- rectal carcinoid tumors;
- gastric carcinoid tumors;
- Carcinoid tumors of colon.
Basically, tumors of the small intestine (regardless of whether it is benign or malignant) are rare, much less often than the tumor of colon or stomach. Be that as it may, carcinoid tumors are 1/3 of all small tumors and is more often known as the iliac tumor (the lower part of the small intestine, next to the colon). Small carcinoid tumors of the small intestine do not give any symptoms, only unspeakable abdominal pain.
For this reason, it is difficult to determine the presence of a carcinoid tumor of the small intestine at an early stage, at least, until the patient has been operating. It is possible to detect only a small part of the carcinoid tumors of the small intestine in the early stages, and that this happens unexpectedly when x-ray. Usually carcinoid tumors of the small intestine are diagnosed in the later stages, when the symptoms of the disease made itself felt and usually after the local and remote metastases began.
Approximately 10% of carcinoid tumors of the small intestine serve as the occurrence of carcinoid syndrome. Usually the presence of carcinoid syndrome means that the tumor is malignant and reached liver.
Despite the fact that the tumors in the field of appendix are quite rare, carcinoid tumors are the most common tumors in the field of appendix, including approximately half of all appendicular tumors. In fact, carcinoid tumors are found in 0.3% cases of remote appendixes, but most of them do not reach the size of more than 1 cm and does not cause any symptoms.
In most cases, they are found in appendixes remote by non-tumor reasons. Representatives of many institutions believe that appendectomy is the most appropriate treatment for such small appendicular carcinoid tumors. The chances of the fact that the tumor recurns after appendectomy, very low. Appendicular carcinoid tumors of more than 2 cm in size during diagnosis have approximately 30% chance to turn into malignant and have local metastases.
Thus, carcinoid larger tumors should be deleted. Simple appendectomy in this case will not help. Fortunately, carcinoid tumors of large size are quite rare. Carcinoid tumors in appendix, even if there are metastases in local tissues, are usually the cause of carcinoid syndrome.
Rectal carcinoid tumors are often diagnosed by chance when performing plastic sigmoidoscopy or colonoscopy. Carcinoid syndrome is rarely found in rectal carcinoid tumors. The probability of occurrence of metastases (malignant carcinoid tumor) is correlated with a tumor size; 60-80% of the chances of the occurrence of metastases exists with tumors of more than 2 cm.
With carcinoid tumors of less than 1 cm 2% chances of the occurrence of metastases. Thus, small rectal carcinoid tumors are usually successfully deleted by simple removal, but to combat larger tumors (more than 2 cm), an extensive surgery is needed, which can lead, in some cases, even to partial rectal removal.
There are 3 types of gastric (gastric) carcinoid tumors: Type I, type II and type III.Gastral carcinoid tumors of the first type are usually less than 1 cm and, as a rule, are benign. There are complex tumors that apply throughout the stomach. They usually appear in patients with diseases in which the stomach ceases to produce acid.
Treatment of carcinoid tumors of the first type includes such methods as the reception of drugs that stop the production of gastrophs or surgical removal of the part of the stomach that produces gastrin.
The second type of garcinoid tumor is resolved less often, such tumors grow very slowly and the likelihood of their transformation into a malignant tumor is very small. They appear in patients with rare genetic violation. In such patients, tumors occur in other endocrine glands, such as epiphysis, parachitoid gland and pancreas.
The third type of garcinoid tumor is tumors of more than 3 cm, which are separate (appearing in one or two at the same time) in a healthy stomach (this does not apply to the presence of pernicious anemia or chronic atrophic gastritis). Third type tumors are usually malignant and there is a high probability of their deep penetration into the walls of the stomach and the occurrence of metastases. Third-type tumors can cause local symptoms of pain in the abdomen and bleeding areas, as well as symptoms due to carcinoid syndrome. Third-type gastral carcinoid tumors typically require surgical intervention and stomach removal, as well as nearby lymph nodes.
Karcinoid tumors of colon usually occur in the right part of the colon (afferent colon and right half of the transverse colon). Like carcinoid tumors of the small intestine, the carcinoid tumors of the colon are often found in the later stages. Thus, the average tumor size in diagnosing is 5 cm, and metastases are present in 2/3 patients.
