Carcinoid syndrome is a complex of different symptoms that occur together. Tumors usually represent the cause of the disease. Their development is related to so-called neuroendocrine systems. The focus is on a tumor that produces the neurotransmitter serotonin and is itself neuroendocrine in nature. In numerous cases, carcinoid syndrome causes symptoms only in late stages, so that the diagnosis of the disease is often delayed for a long time.
What is carcinoid syndrome?
In carcinoid syndrome, a neuroendocrine tumor triggers various symptoms in affected patients. For example, the main symptoms of carcinoid syndrome are diarrhea, pain in the area of the abdomen, sudden redness of the skin, and problems with breathing. The cardiovascular system may also be affected by the disease. Carcinoids appear in the form of neoplasms that are epithelial and neuroendocrine in nature. They also have hormonal activity. They produce various substances, such as serotonin, kallikrein or histamine. The name of the disease is derived from the corresponding tumor. Its discovery in 1907 goes back to Oberndorfer. In principle, it is possible that the tumor affects all neuroendocrine tissues. However, in the majority of cases, the tumor forms in the lung, colon, stomach or appendix. The tumors differ from others in their external appearance as well as in their coloration. In some circumstances, they develop in individuals suffering from hypergastrinemia. This is a condition in which the substance gastrin is increasingly secreted into the blood. This is the case, for example, in what is known as Zollinger-Ellison syndrome.
Causes
The cause of carcinoid syndrome is primarily due to the excessive release of the neurologic neurotransmitter serotonin. Certain neuroendocrine cells are responsible for this release. There is a degeneration of these cells. In this way, the function of the liver is altered. The cells of the liver contain the so-called monoamine oxidase, which acts as a catalyst for the decomposition of serotonin from the tumor. In this process, the serotonin is converted into the substance 5-hydroxyindoleacetoacetic acid, which no longer has any biological activity. For this reason, the concentration of the substance in the patients’ urine can be used to make the diagnosis.
Symptoms, complaints, and signs
The spectrum of possible symptoms of carcinoid syndrome is relatively broad. First and foremost, the hallmark symptoms of the disease include seizure-like diarrhea associated with abdominal cramps and watery stools. During these phases, the face also often turns reddish to purple. Similar discolorations of the skin may also appear in the area of the legs or neck. If the carcinoid syndrome remains without therapy, various complications are the result in some cases. For example, defects of the heart valves, a deficiency of vitamin B2 and so-called telangiectasia are possible. In the majority of cases, the tumors develop in the area of the gastrointestinal tract. The appendix and the ileum are particularly frequently affected by carcinoids. In addition, occurrence in the lungs is also possible. If the tumors metastasize, this usually occurs in the liver. The typical symptoms are primarily caused by a sudden increase in the concentration of vasoactive substances in the organism. The so-called flush manifests itself in symptoms such as increased sweat production, palpitations and reddened skin. In addition, some patients complain of hot flashes. Diarrhea is also caused by the corresponding substances. However, most of the symptoms do not become apparent until the tumors have already metastasized to the liver. For this reason, diagnosis often takes place relatively late.
Diagnosis and course of the disease
A large proportion of patients do not show typical symptoms of carcinoid syndrome until the tumors have metastasized to the liver. Thus, the disease is often diagnosed at a late stage. If the presence of carcinoid syndrome is suspected, a specialist should be consulted who will discuss the symptoms with the patient and find out about his or her lifestyle and any chronic diseases.Finally, important indications of the disease at hand are gathered through the use of various examination methods. First and foremost, an analysis of the urine is used to determine the concentration of the substance 5-HIAA. If the threshold values are exceeded, the carcinoid syndrome can be diagnosed with relative certainty. In addition, imaging methods and examinations of tissue samples are used. An important role is played by the differential diagnosis, in which, for example, enzyme defects in connection with serotonin or histamine must be clarified. Possible causes here include intolerance to the substance histamine or migraine attacks.
Complications
As a result of carcinoid syndrome, the affected person suffers from various tumors that may be located throughout the body. This results in the usual symptoms and complications of cancer, which can also significantly reduce the life expectancy of the affected person. In many cases, carcinoid syndrome is diagnosed late, resulting in irreversible sequelae and premature death of the patient. Malformations and defects of the heart occur, which can lead to cardiac death. Similarly, carcinoid syndrome not infrequently leads to discoloration of the skin or face. Patients suffer from severe diarrhea and abdominal pain. Furthermore, there are also hot flashes or sweating. Patients also suffer from palpitations and may lose consciousness. The quality of life is significantly reduced by the carcinoid syndrome. Treatment of carcinoid syndrome does not usually lead to any particular complications. However, a positive course of the disease does not occur in every case. The tumors are surgically removed. The affected person is dependent on taking various medications and on regular check-ups to prevent further tumors from developing.
When should one go to the doctor?
If gastrointestinal complaints, unusual discoloration of the face, and other typical symptoms of carcinoid syndrome are noticed, a visit to the doctor is recommended. Sudden sweating, rapid heartbeat or reddened skin are also warning signs that need to be clarified quickly. Symptoms of deficiency and signs of cardiac arrhythmia indicate that the disease has already progressed. At the latest then, a doctor should be consulted who can clarify the symptoms and complaints and, if necessary, initiate treatment. Since the disease is usually only discovered in the late stages, treatment must be started immediately. Close consultation with the responsible physician should be maintained during treatment. In the event of unusual symptoms or side effects and interactions, the patient must inform the doctor, otherwise serious complications may develop. The correct contact person is the family doctor or an internist. Patients in whom the syndrome occurs in the context of another disease are best advised to speak to the physician in charge. Children should be presented to a pediatrician immediately.
Treatment and therapy
Treatment of carcinoid syndrome should be started immediately after diagnosis because the disease is usually discovered late. The treatment of choice is removal of the primary tumor, which is performed as part of a surgical procedure. Metastases must also be removed. Another option is the administration of agents that slow the growth of the tumors.
Outlook and prognosis
The prognosis for carcinoid syndrome depends on several factors. In the early stages of the disease and with good general health, cure is quite possible. If the patient complies with the physician’s instructions and medical measures are initiated immediately, there is a chance of recovery. Nevertheless, this requires surgical removal of the tumors and the use of cancer therapy. Both are associated with numerous side effects and risks. Complications can occur that contribute to a worsening of the prognosis. In most cases, several tumors have already formed in the organism at different sites in a carcinoid syndrome. They pose a potential threat to the patient’s life. If the body is already severely weakened due to a previous disease and a large number of cancer cells have formed, the prospect of recovery dwindles.In addition, the disease is often only noticed at an advanced stage of development. This complicates treatment and diminishes the prospect of health improvement. If the growth of the tumors cannot be contained and ultimately prevented completely, the patient will die prematurely. If metastases form, the prognosis deteriorates further. In the final phase of the disease, physicians are mainly concerned with alleviating the unpleasant symptoms.
Prevention
Currently, there are no known measures to prevent carcinoid syndrome.
Follow-up
In carcinoid syndrome, very few or no aftercare measures are available to the patient in most cases, so the affected person is primarily dependent on rapid and, above all, early diagnosis for this disease. There can be no self-healing in this case, and early detection of the disease usually always has a very positive effect on the further course of the disease. As a rule, the tumor must be removed in carcinoid syndrome. The further course of the disease depends strongly on the type and also the extent of the tumor, so that a general prediction is not possible here. However, the patient should rest and take care of his body after the operation. They should refrain from physical exertion or stressful activities. The support of one’s own family or friends is also very important in the case of carcinoid syndrome, whereby loving and intensive conversations are also necessary so that no psychological complaints or depression can occur. In many cases, however, the carcinoid syndrome significantly reduces the life expectancy of the affected person, because the syndrome is detected late.
What you can do yourself
In most cases of carcinoid syndrome, there are no self-help options available. Affected individuals rely on further testing to identify the primary disease or tumor when the syndrome is diagnosed. In addition to the physical symptoms, many of those affected also suffer from mental illness or depression. In this case, it is advisable to discuss the disease and its further course with the closest confidants and with the family. Children in particular should be informed about the disease, and the possible negative consequences should also be mentioned. It is often helpful to talk to other patients who can provide helpful information. However, psychological treatment can also be useful for the patient’s relatives, partner or parents. Patients with carcinoid syndrome should take it easy and not put unnecessary strain on their bodies. As a rule, sporting activities should also be avoided. After the tumors have been removed, patients are dependent on regular examinations to prevent recurrence of the disease.
