Carcinoid tumors are relatively rare. Carcinoid tumors originate in the hormone-producing cells of the GI tract, respiratory tract and gallbladder, liver or reproductive glands. About half of all GI and pancreatic tumors are carcinoids. There are about 5000 cases of carcinoid tumor every year in the US. Not all carcinoid tumors are malignant. Typically carcinoid tumors that primarily develop outside the appendix are often malignant, while tumors developing in the appendix usually are benign. Patients suffering from carcinoids are at increased risk for Cushing's Syndrome. Read up about lung carcinoid and carcinoid tumor syndrome.
Carcinoid tumors are often referred to as carcinoids and affect the neuro-endocrine system. Most carcinoid tumors are found in the appendix or small intestine. Sometimes they are also noticed in the lungs or pancreas. It is rare for them to appear in other parts of the body. A carcinoid develops within the peptide and amino-producing cells. Such tumors grow slowly. The actual cause of carcinoid tumors is not known but it is suspected that there is a genetic connection. The location of the carcinoid and its extent of spread affect the nature of symptoms.
When carcinoid tumors are restricted to the GI tract, there may not be any noticeable symptoms since the hormones produced are released into the bloodstream and destroyed by the liver. There may be symptoms such as GI bleeding, abdominal pain and weight loss. Other carcinoid tumors produce hormones that are not destroyed by the liver thereby leading to excess levels of hormones circulating in the blood. This condition is known as carcinoid syndrome.
A day's collection of urine is checked for raised serotonin levels. X-rays and scans help in detecting the spread of the carcinoid tumor. CT scans and MRI scans help in locating where the tumor originates and the extent of spread. A mildly radioactive drug called 123MIBG is used to detect the site of a carcinoid tumor. Many a time a biopsy of the tumor is taken for examination to check for malignancy.
Chemotherapy is used to treat carcinoid tumors. The tumor is reduced and so is the serotonin secretion. Radiotherapy is given to patients suffering from carcinoid tumors, especially those that have spread to the bones. Radiotherapy with 131MIBG is known to reduce the number of carcinoid cells and symptoms of carcinoid syndrome. Surgery with complete removal of the carcinoid tumor tissue is usually the first line treatment. It can result in permanent cure. Even removal of large portions of the carcinoid tumor can greatly alleviate symptoms. Interferon is an immuno-modulator that arrests further growth of the carcinoid.
When a carcinoid tumor produces serotonin that is not synthesized by the liver, symptoms of carcinoid syndrome are exhibited. The person may notice flushed skin, wheezing, loss of appetite, diarrhea and weight loss. A person thought to be suffering from carcinoid syndrome is subject to blood and urine tests to determine the levels of bio-active substances that are secreted from carcinoid tumors. Some patients develop heart disease. Symptoms of carcinoid syndrome depend on which hormones are produced by the tumor. Flushing episodes are one of the most common symptoms of carcinoid syndrome. This can be spontaneous or triggered by stress, exercise or alcohol. Other symptoms include bluish tint to the skin, enlargement of peripheral body parts, skin lesions, heart damage and reduced libido.
Increased protein and a low-fat diet are often recommended for carcinoid tumors. Multivitamin mineral and low-dose nicotinic acid supplements may also be prescribed. Fish oil capsules, electrolyte supplements and in some cases, large portions of nutmeg may be recommended for those suffering from carcinoid.
Lung carcinoids may be of 2 kinds - typical or atypical. Typical lung carcinoids grow slowly and rarely spread outside of the lungs. On the other hand, atypical carcinoids grow more rapidly. Each year there are nearly about 1700 newly diagnosed lung carcinoid cancers in the US each year. Lung carcinoids are usually small, in the range of ¼ - ¾ inch. The treatment for lung carcinoid tumors is based on the size and location and extent of spread.