Carcinoid Syndrome (CS) is a collection of symptoms that are linked to carcinoid tumours. Tumors of the small intestine, colon, appendix, and bronchial tubes in the lungs are all examples of this.

Carcinoid syndrome is a set of symptoms induced by the systemic production of humoral factors such as polypeptides, biogenic amines, and prostaglandins, which are mostly released by well-differentiated neuroendocrine tumours.

Carcinoid tumours were formerly referred to be well-differentiated neuroendocrine tumours. Enterochromaffin cells, which are found throughout the body, are the source of neuroendocrine tumours. Only approximately 10% of neuroendocrine tumours develop in carcinoid syndrome, according to reports.

Flushing and diarrhea are the most common symptoms. Wheeze, palpitations, telangiectasia, and stomach discomfort are some of the other symptoms.

Elevated amounts of 5-hydroxyindoleacetic acid in the urine are used to diagnose the condition. When there are liver metastases, chromogranin A levels are frequently increased.

Medical treatments (somatostatin analogues, radionuclide therapy) and surgical alternatives are available (resection of primary and secondary tumors).

Carcinoid heart disease and carcinoid crises during times of stress are examples of complications (e.g., during surgery).


In individuals with carcinoid tumours, the carcinoid syndrome (CS) is a symptom combination caused by hormone production.

Carcinoid tumours are known for their sluggish growth, and patients often live for many years after being diagnosed. Only when adequate concentrations of hormones reach the systemic circulation, which most usually occurs in the presence of liver metastases, does CS emerge. This Fast Fact will focus on CS symptom management.

What is the definition of Carcinoid Syndrome?

Carcinoid tumours begin in the neuroendocrine system, which includes the appendix, intestine, pancreas, lungs, stomach, ovaries, kidneys, and testicles. NETs, or neuroendocrine tumours, are another name for these tumours.

The growth and spread of a carcinoid tumour are both gradual. It can, once it has spread, emit substances that cause carcinoid sickness.

Carcinoid Syndrome

 Carcinoid Syndrome

Carcinoid syndrome is a collection of symptoms and indicators that are linked to carcinoid tumours. The appearance of these symptoms and indicators typically indicates that a malignant carcinoid tumour has spread (i.e.: cancer has spread to the liver and possibly to other organs).

Flushing, diarrhoea, intermittent stomach discomfort, wheezing, heart palpitations, and low blood pressure are all common symptoms of carcinoid syndrome.

Carcinoid syndrome is characterized by flushing, which occurs in 75 percent of patients. This is due to a temporary dilatation of blood vessels.

  1. The face, head, neck, chest, and epigastric regions are all affected by flushing.
  2. It might last anywhere from 2 to 5 minutes to a few hours (particularly in the later stages of the disease).
  3. There may be a widespread or mottled appearance to the skin, with or without oedema (swelling).
  4. Frequent flushing can cause long-term skin abnormalities including telangiectasia (broken blood vessels) and plethora (excessive sweating) (persistent redness).
  5. Stress, hot meals, chocolate, wine, and cheese can all cause flushing.

Dermatitis, which is similar to pellagra, can also develop. In places exposed to sunlight, the symptoms include reddish skin with superficial scaling.


Carcinoid tumours have an unknown underlying aetiology. Some studies have shown that smoking and food consumption are risk factors, although further study is needed to validate these conclusions.

Tumors can create hormonal chemical compounds such as serotonin, bradykinins, tachykinins, and prostaglandins in the majority of instances. If the carcinoid cells travel to the liver (metastasize), these compounds are no longer broken down to their inactive state and are released into the systemic (main) circulation, resulting in carcinoid syndrome signs and symptoms.

Carcinoid Syndrome

Carcinoid Syndrome

Carcinoid syndrome can develop in the absence of liver metastases when tumours affect organs other than the gastrointestinal system, such as the ovaries.


It affects both men and women equally, and it is most frequent in people between the ages of 40 and 70.

Clinical manifestations

The most frequent and first symptom is diarrhea, although additional symptoms include flushing, right heart failure, discomfort, and bronchospasm.


Carcinoid syndrome can develop as a paraneoplastic disease in the context of a carcinoid tumour, the most frequent of which is a carcinoid of the gastrointestinal system.

Hepatic metastatic illness, generally from a primary bowel carcinoid tumour, is often indicated by the presence of the carcinoid syndrome.


The signs and symptoms of carcinoid syndrome are determined by the substances secreted into your system by the carcinoid tumour.

Carcinoid Syndrome

Carcinoid Syndrome

The following are the most prevalent signs and symptoms:

1. Flushing of the skin

Your face and upper chest skin becomes heated and changes colour, ranging from pink to purple. Flushing attacks can last anywhere from a few minutes to many hours or more. Flushing can occur for no apparent cause, but it can also be provoked by stress, exercise, or binge drinking.

2. Skin lesions on the face

On your nose and upper lip, purplish streaks of spiderlike veins may emerge.

3. Diarrhea

Carcinoid syndrome patients may experience frequent, watery faces that are occasionally accompanied by stomach pains.

4. Breathing problems

Wheezing and shortness of breath, which are asthma-like signs and symptoms, may occur at the same time as skin flushing.

5. A pounding hearts

Carcinoid syndrome can be identified by periods of rapid heart rate.

Diagnosis of Carcinoid Syndrome

If your doctor suspects you have carcinoid syndrome, he or she will do a physical examination and ask you questions such as:

  1. Have you ever noticed your skin becoming red and feeling heated or burning?
  2. Do you get diarrhea on a regular basis?
  3. Have you been out of breath recently?
  4. Do you have a tendency to wheeze?

You may also require testing to rule out the presence of a carcinoid tumour.

A urine test is performed: Over the course of a 24-hour period, you collect your urine in containers. High quantities of hormones, or what’s left after your body breaks them down, will be tested in a lab.

A blood test is required: This might also reveal the compounds released by tumours.

Imaging tests are performed: A CT scan is a sequence of X-rays that shows the inside of your body in great detail. Strong magnets and radio waves are used in an MRI to create images of your organs. Your doctor will inject you with a little quantity of radioactive material, which will be absorbed by your organs during radionuclide scanning. A sophisticated camera can detect the substance and provide images that can aid your doctor in locating a tumour.



After a comprehensive review, surgery to remove the main tumour and debulk liver metastases may be undertaken in carefully chosen individuals. Depending on the size and location of the tumour, lobectomy, sleeve resection, or pneumonectomy may be done for airway lesions.

Injections of Somatostatin Analogs

Injections of a somatostatin analogue (Sandostatin, Lanreotide) may help with carcinoid syndrome symptoms including skin flushing and diarrhea. Somatostatin analogues are synthetic versions of the pancreatic hormone somatostatin.

Locoregional Therapies

Radiofrequency ablation uses a needle to deliver heat to metastatic cells in the liver, forcing them to die. Cryotherapy, on the other hand, works by freezing the tumour. Microwave ablation (MWA) is a novel method that uses microwave radiation to eliminate liver tumours.


Chemotherapy medicines have the potential to reduce neuroendocrine tumours, particularly those of the pancreas. Chemotherapy regimens based on temozolomide, fluorouracil, oxaliplatin, and streptozocin are among them.

Other Medications

There are other anti-diarrheal and anti-cholinergic medicines employed. Patients are recommended to avoid alcohol and foods high in tyramine, since these might exacerbate symptoms.

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