Carcinoid tumors are a slow-growing type of cancer that can arise in several places throughout your body. Carcinoid tumors usually appear in the gastrointestinal tract (appendix, stomach, small intestine, colon, and rectum) and in the lungs. But, carcinoid tumors can also begin in other organs, including the ovaries and testes. Carcinoid tumors rarely 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.

Complications of Carcinoid Tumor

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

• Stomach ulcers. Carcinoid tumors, particularly those in the stomach, can secrete a hormone that increases acid in the stomach, which can lead to ulcers.
• Carcinoid syndrome. Carcinoid syndrome causes redness or a feeling of warmth in your face and neck (skin flushing), chronic diarrhea, and difficulty breathing, among other signs and symptoms.
• Carcinoid heart disease. Carcinoid tumors may secrete hormones that can cause thickening of the lining of heart chambers, valves and blood vessels. This can lead to leaky heart valves, an enlarged heart and heart failure. Carcinoid heart disease can usually be controlled with medications and surgery.
• Cushing's syndrome. A lung carcinoid tumor can produce an excess of a hormone that can cause your body to produce too much of the hormone cortisol.
• Acromegaly. Another hormone secreted by some lung carcinoid tumors can cause this rare hormone disorder. Acromegaly causes bones to increase in size, including the hands, feet and face.

Causes of Carcinoid Tumor

Cancer occurs when a cell develops a mutation in its DNA. The mutation allows the cell to continue growing and dividing when healthy cells would normally die. In the case of carcinoid tumors, the accumulating cells form a mass. Cancer cells can invade nearby healthy tissue and spread to other parts of the body. It's not clear what causes the mutations that can lead to carcinoid tumors. Carcinoid tumors develop from cells in the neuroendocrine system, a part of your body that has many functions, including production of certain hormones. These cells also have characteristics similar to nerve cells.

Signs & Symptoms of Carcinoid Tumor

In many cases, 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. Signs and symptoms of carcinoid tumors may include:

• Abdominal pain
• Bowel obstruction
• Changes in bowel movements
• Chest pain
• Diarrhea
• Difficulty breathing
• Rectal bleeding
• Rectal pain
• Recurrent pneumonia
• Redness or a feeling of warmth in your face and neck (skin flushing)

Diagnosis of Carcinoid Tumor

Tests and procedures used to diagnose carcinoid tumors include:

• Blood test. If you have a carcinoid tumor, your blood may contain high levels of a protein caused by hormones secreted by a carcinoid tumor.
• Urine test. People with carcinoid tumors have excess levels of a chemical in their urine that's produced when the body breaks down hormones secreted by carcinoid tumors.
• Imaging tests. Imaging tests, including a computerized tomography (CT) scan, magnetic resonance imaging (MRI), positron emission tomography (PET), ultrasound, octreotide scan and X-ray, may help your doctor pinpoint the carcinoid tumor's location.
• Using a scope or camera to see inside your body. Your doctor may use a long, thin tube equipped with a lens or camera to examine areas inside your body. An endoscopy, which involves passing a scope down your throat, may help your doctor see inside your gastrointestinal tract. Bronchoscopy, using a scope passed down your throat and into your lungs, can help find lung carcinoid tumors. Passing a scope through your rectum (colonoscopy) can help diagnose rectal carcinoid tumors. To see inside your small intestine, your doctor may recommend a test using a pill-sized camera that you swallow (capsule endoscopy).
• Biopsy. A sample of tissue from the tumor (biopsy) may be collected to confirm your diagnosis. What type of biopsy you'll undergo depends on where your tumor is located. In some cases a surgeon may use a needle to draw cells out of the tumor. In other cases, a biopsy may be collected during surgery. The tissue is sent to a laboratory for testing to determine the types of cells in the tumor and how aggressive those cells appear under the microscope.

Treatments of Carcinoid Tumor

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.

Treatments can include:

Surgery

When detected early, a carcinoid tumor may be removed completely using surgery. Most carcinoid tumors are advanced when discovered, so complete removal may not be possible. In some cases, surgeons may try to remove as much of the tumor as possible, to help control signs and symptoms. What types of operations are available to you will depend on the size and location of your carcinoid tumor.

Treatments for carcinoid tumors that have spread to the liver

Carcinoid tumors commonly spread (metastasize) to the liver. Options may include:

• Liver surgery. Surgery to remove part or all of the liver (hepatic resection) may control signs and symptoms caused by liver tumors.
• Stopping blood supply to liver tumors. Using hepatic artery embolization, a doctor can clog the liver's main artery (hepatic artery), cutting off the blood supply to cancer cells that have spread to the liver. Healthy liver cells survive by relying on blood from other blood vessels.
• Killing cancer cells with heat or cold. Radiofrequency ablation delivers heat treatments that cause carcinoid tumor cells in the liver to die. Cryoablation uses cycles of freezing and thawing to kill cancer cells.

Medications for carcinoid syndrome

Injections of medications may block tumor cells from secreting the hormones that can cause the signs and symptoms of carcinoid syndrome. Octreotide (Sandostatin) and lanreotide (Somatuline Depot) may help control flushing and diarrhea in most people with carcinoid syndrome. Both drugs are injected once a month and may cause side effects such as abdominal pain and bloating, diarrhea, and nausea. Side effects typically diminish over time.

When to seek Medical Advice

Carcinoid tumors often don't cause any signs and symptoms. If you experience any signs and symptoms that bother you and are persistent, make an appointment with your doctor.