Carcinoid tumors are rare, slow-growing neuroendocrine tumors.
Diagnosis of carcinoid tumors depends on the characteristic biomarker of the disease. Measuring the biogenic amine (such as serotonin, histamine, and catecholamines) levels as well their metabolites in the plasma is important to diagnose the carcinoid tumor.
Imaging techniques that can diagnose carcinoid tumors are as follows:
Depending on the type and location of the tumor, a combination of either of these can be used. For chest tumors, CT along with scintigraphy is used. Large bowel disease is often diagnosed by colonoscopy. Mesenteric invasion and liver metastasis can be detected by CT scans. For hepatic disease, MRI can be helpful in the diagnosis of the condition. PET scanning is helpful for the diagnosis and follow-up of the tumors. Radionuclide imaging has proven to be the best diagnostic tool for the diagnosis of carcinoid tumors. Somatostatin-receptor scintigraphy (SRS) and CT scanning can help detect localized tumors   .
Medical care: In case where the surgical excision is not suitable in patients with carcinoid tumor, the following chemotherapy drugs are recommended. Alkylating agents, doxorubicin, actinomycin D, cisplatin, interferon-alfa and streptozocin are some of the drugs that are used to manage the condition. In most of the cases, a combination of the agents is used.
Chemoembolization is one of the strategies for the management of carcinoid tumors. Though octreotide has been found to be very effective in reducing the symptoms, its use in pediatric population is still debated, as it reduces the level of growth factor which is produced impairing growth  .
Surgical care: The surgical excision as a treatment choice depends on the feasibility of the condition. Surgical technique depends on the location and the stage of the tumor. Simple appendectomy is the treatment option in most of the cases.
Block resection of the tumor (with the adjacent lymph nodes) is a surgical treatment adopted for intestinal carcinoids, while in case of bronchial tumor, surgical resection is opted. In most of the localized tumor, surgical resection works. For managing rectal tumor, endoscopic resection is sufficient. Debulking can provide symptomatic relief in patients when total resection is not possible   .
Prognosis in the patients with carcinoid tumors depends on some important factors such as the location and size of the tumor, if the tumor has spread to other parts of the body, or if the tumor can be removed completely by surgery or if it recurred or was diagnosed for the first time.
Carcinoid tumors secrete chemicals which can lead to complications such as carcinoid syndrome (skin flushing, chronic diarrhea, problems in breathing), carcinoid heart disease (leaky heart valves, and heart failure) and Cushing syndrome.
Carcinoids are the most common neuroendocrine tumors. The true incidence of this type of tumor is still not clear. Though it is estimated to be around 1 every 100,000 individuals, there are some studies that have shown necropsies in approximately 1% of the population .
The carcinoid tumors are of neuroendocrine origin. These tumors are derived from the primitive stem cells, giving rise to the multiple cell lineages. These tumors develop in the mucosa of the intestinal tract and grow slowly, extending to the submucosa and mucosal surface, resulting in the formation of small nodules.
The tumors are yellow, or gray-brown in color, due to the accumulation of cholesterol and lipids. Metastases can also occur in the liver, spleen, peritoneum, liver and the ovaries. Five distinct patterns of the carcinoid tumors are observed upon histological examination.
Some of the products of the carcinoid tumors are amylin, dopamine, gastrin, bombesin, catecholamines, motilin, pancreatic polypeptide, prostaglandins, serotonin, somatostatin and substance-P. The carcinoid tumors are found to be argyrophilic and argentaffinic, with somatostatin receptors. There is a high potential for metastasis in carcinoid tumors as these cells produce betacatenin  .
Carcinoid tumors are derived from primitive stem cells, present in the gut wall, and other organs such as thymus, lungs, liver, ovaries, prostate and kidneys. Among children, carcinoid tumors are seen in the appendix which are benign and asymptomatic.
Most of these tumors are slow-growing and asymptomatic, though some are aggressive and metastatic. Carcinoid tumors can be classified based on the location of the primitive gut giving rise to the tumor such as foregut, midgut and hindgut.
Meckel diverticulum, mesentry and cystic duplications can also lead to the development of carcinoid tumors. These entities have shown distinctive features: clinical, histochemical, and secretory. While both foregut and hindgut carcinoids are argentaffin negative, the midgut carcinoids are argentaffin positive. Foregut tumors can metastasize to the bone and can be associated with acromegaly, Cushing’s disease, and hypertrophy of the skin of the face and the upper neck. In midgut and hindgut carcinoids, the bone metastasis is uncommon, though midgut carcinoid tumors have the rare potential to produce the corticotropic hormone .
Carcinoid tumors are derived from primitive stem cells, present in the gut wall, and other organs such as thymus, lungs, liver, ovaries, prostate and kidneys. There are no specific symptoms of the disease, however since there is a genetic component in the pathogenesis of the disease, any family member diagnosed earlier with carcinoid tumor adds to the risk of this disease in the sibling or children. Hence, in such cases, the patient must not neglect any possible signs and symptoms.