Carcinoid tumors

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at May 25, 2016
StartDiseasesCarcinoid tumors

A carcinoid tumor is a very rare type of cancer that grows slowly. Most carcinoid tumors begin in the lungs or the lining of the digestive tract. Since these tumors don't create any symptoms during the early stages, many adults don't receive a diagnosis until they are in their 60s.


Definition & Facts 

A carcinoid tumor is known as a neuroendocrine tumor. Neuroendocrine cells perform various functions in the body, including regulating air and blood flow through the lungs and controlling the speed that food moves through the digestive system.

A carcinoid tumor usually develops in the stomach, intestines or lungs. About 30 percent of tumors start in the small intestine. Nearly 15 percent begin in the rectum. Close to 10 percent start in the lungs, and 7 percent start in the appendix. In decreasing order, they can also occur in the colon, stomach, pancreas, and rarely, the liver

Symptoms & Complaints 

Carcinoid tumors are unlikely to produce many symptoms early on. However, if symptoms arise they are typically due to tumors of the gastrointestinal tract.

There are several potential symptoms that someone who has a GI carcinoid tumor may experience. Facial flushing that manifests as redness and a warm feeling in the face could be a sign of a tumor. Additionally, diarrhea, abdominal pain, asthma, and a rash are common symptoms.

Some people may develop heart disease and intestinal bleeding. More serious symptoms include something known as pellagra where scaly sores appear on the body. Pellagra may also cause emotional instability. Melena is another side effect, and it usually manifests as dark, tarry stools that indicate bleeding in the digestive tract.

Symptoms are less likely in individuals who have a lung-based carcinoid tumor. However, when symptoms do appear, they manifest as a cough or wheezing. A cough may be present with blood, sputum, and phlegm, but a prolonged cough by itself may be a sign. In some instances, carcinoid tumors can manifest as a type of infection such as pneumonia when the tumor has blocked an air passage. 


The causes of carcinoid tumors are numerous, but there are certain factors that may increase the risk of a person developing a tumor. Family history of tumors put individuals at a higher level of risk since many of these tumors are hereditary. Race and gender may also play a role and there is a higher percentage of African Americans who have tumors than Caucasians. Men and women tend to have the same level of risk, but women tend to live longer once treatment has been completed.

People who have a history of gastrointestinal disease may have a greater risk of developing a tumor. Additionally, people who have pernicious anemia are at greater risk. This type of anemia exists when people cannot make enough red blood cells because the body cannot properly absorb vitamin B12. It's helpful to discuss any risk factors with a doctor so early screening can help detect these tumors.

Diagnosis & Tests 

Diagnostic testing is based on several factors, and a doctor considers the age of the patient, medical condition, type of suspected tumor and previous blood tests to first make an educated guess. X-rays may reveal a tumor, but these are usually accidental discoveries. An individual preparing to get his or her appendix removed may reveal a tumor in the stomach.

In most cases, the only test that reliably indicates whether a tumor exists is a biopsy. This is essentially when a doctor takes a sample of tissue from the suspicious area and examines it. In cases where a biopsy isn't possible, there may be other tests available to determine if there is cancer. When a biopsy isn't possible, the doctor may run blood or urine tests to find out if there are unusual levels of hormones which may be indicative of carcinoid tumors.

An endoscopy is a test that allows a doctor to use an endoscope to examine the upper digestive system to check for abnormalities. Additionally, an endoscopic ultrasound uses sound waves that create a picture of the internal organs. Other possible tests include CT scan, MRIs, and PET scans. All of these scans can help to detect possible tumors in the body.

Treatment & Therapy

There will typically be more than one doctor working with a patient, and the team may consist of oncologists, nurses, social workers, pharmacists, counselors, nutritionists and other professionals. One option for treatment is surgery. Depending on the location of the tumor, it may be possible to surgically remove the tumor. During surgery, the surgeon may remove some non-cancerous tissue as well in an effort to remove the cancerous tissue. There are different types of incisions that can be made, and the type of surgery depends on the the degree that the cancer has metastasized or spread and the location.

If the cancer has spread, then there are various types of radiation and chemotherapy that may be available to patients. Additionally, in some cases, immunotherapy may be used to help improve the immune system. This type of surgery uses the immune system and materials made by the body or in a lab to help restore immune system function. This type of therapy may reduce a tumor or slow its growth. Finally, targeted therapy may be used to target the specific genes, proteins or tissue of the cancer to stop its growth.

Prevention & Prophylaxis

Good nutrition and regular exercise are often recommended as preventative measures, though carcinoid tumors are typically not preventable cancers, as their known risk factors are primarily age, family history, race and ethnicity, and history of gastrointestinal disease and anemia.

For those who have undergone treatment, regular physical examinations are conducted. The patient and doctor must stay alert to any symptoms that may indicate the cancer has returned. By watching for recurrence, doctors may be able to prevent the cancer from spreading before it is too late. There will be side effects from treatment in the form of physical and emotional changes, so it's important to talk with a doctor and prepare for any challenges.