Carcinoid tumors are a type of slow-growing cancer that can arise in several places throughout your body. Carcinoid tumors, which are one subset of tumors called neuroendocrine tumors, usually begin in the digestive tract (stomach, appendix, small intestine, colon, rectum) or in the lungs.

Carcinoid tumors often don’t cause signs and symptoms until late in the disease. Carcinoid tumors can produce and release hormones into your body that cause signs and symptoms such as diarrhea or skin flushing.

Treatment for carcinoid tumors usually includes surgery and may include medications.

Some carcinoid tumors don’t cause any signs or symptoms. When they do occur, signs and symptoms are usually vague and depend on the location of the tumor.

Carcinoid tumors in the lungs

Signs and symptoms of carcinoid lung tumors include:

Carcinoid tumors in the digestive tract

Signs and symptoms of carcinoid tumors in the digestive tract include:

When to see a doctor

If you experience any signs and symptoms that bother you and are persistent, make an appointment with your doctor.

It’s not clear what causes carcinoid tumors. In general, cancer occurs when a cell develops mutations in its DNA. The mutations allow the cell to continue growing and dividing when healthy cells would normally die.

The accumulating cells form a tumor. Cancer cells can invade nearby healthy tissue and spread to other parts of the body.

Doctors don’t know what causes the mutations that can lead to carcinoid tumors. But they know that carcinoid tumors develop in neuroendocrine cells.

Neuroendocrine cells are found in various organs throughout the body. They perform some nerve cell functions and some hormone-producing endocrine cell functions. Some hormones that are produced by neuroendocrine cells are histamine, insulin and serotonin.

Factors that increase the risk of carcinoid tumors include:

The cells of carcinoid tumors can secrete hormones and other chemicals, causing a range of complications including:

Tests and procedures used to diagnose carcinoid tumors include:

Treatment for a carcinoid tumor depends on the tumor’s location, whether cancer has spread to other areas of the body, the types of hormones the tumor secretes, your overall health and your own preferences.

Carcinoid tumor treatment options may include:

Each person with cancer develops their own way of coping. But you don’t have to do it alone. If you have questions or would like guidance, talk with a member of your health care team. Also consider the following steps to help you deal with your diagnosis:

Make an appointment with your primary care doctor or family doctor if you have signs and symptoms that concern you. If your doctor suspects a carcinoid tumor, you may be referred to a:

Because appointments can be brief, and because there’s often a lot of information to discuss, it’s a good idea to be prepared. Here’s some information to help you get ready, and what to expect from your doctor.

What you can do

Your time with your doctor is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important, in case time runs out. Some basic questions to ask your doctor include:

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may allow more time to cover points you want to address. Your doctor may ask:

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