What is a gastrointestinal carcinoid tumor?

A gastrointestinal carcinoid tumor is a type of cancer that forms in the lining of the gastrointestinal (GI) tract. Also known as the digestive tract, the GI tract includes the stomach, colon, appendix, small intestine and rectum.

Carcinoid tumors start in cells called neuroendocrine cells. Most carcinoid tumors start in the GI tract.

Common related conditions
Colorectal Cancer

Causes of gastrointestinal (GI) carcinoid tumors

It's unclear exactly what causes GI carcinoid tumors. Researchers do know that these tumors form from DNA mutations in the neuroendocrine cells. DNA is the chemical gene within each cell. Certain DNA is supposed to stop cells from growing and dividing. When this DNA mutates, it causes cancerous tumors to form.

Risk factors for gastrointestinal (GI) carcinoid tumors

Your risk for a GI carcinoid tumor increases if you have any of the following conditions:

  • Multiple endocrine neoplasia, type 1 — a rare, inherited defect in the MEN1 gene.
  • Neurofibromatosis type 1 — another inherited disease caused by defects in the NF1 gene.
  • Von Hippel Lindau disease — a hereditary condition that causes tumors.
  • Tuberous sclerosis complex — another rare, inherited disease that causes tumors.

Smokers may have a higher risk of getting this type of tumor. Carcinoid tumors are most common among African Americans. They also occur more often in women than in men.

Symptoms of gastrointestinal (GI) carcinoid tumors

In most cases, people with gastrointestinal carcinoid tumors don't have any symptoms until late in the disease. Sometimes there are no symptoms at all.

GI tumors are often found while the patient receives treatment for something else.

If you do have symptoms, they may include the following:

  • Abdominal pain or bloating
  • Blood in the stool
  • Changes in stool color
  • Constipation
  • Diarrhea
  • Fatigue
  • Flushed skin in the face and neck
  • Heartburn
  • Jaundice (yellowed skin)
  • Nausea
  • Rectal bleeding and/or pain
  • Unexplained weight loss
  • Vomiting

Diagnosis of gastrointestinal (GI) carcinoid tumors

If you're worried that you may have a digestive tract tumor, schedule a visit with your doctor. Your doctor will go over your medical history and give you a physical exam.

The following are some of the tests that can look for a GI carcinoid tumor:

  • Biopsy — this removes tissue, which the doctor can inspect under a microscope.
  • Bone scan — this is a radioactive test to see if cancer is present in your bones.
  • Blood or urine test — these tests check for abnormal hormone levels.
  • CAT scan (CT scan) — this uses 3-D x-rays to take pictures inside the body.
  • Colonoscopy — this uses a small camera to look for problems inside the rectum and colon.
  • Endoscopy — this is a thin tube camera to see the lining of the digestive system.
  • MRI — this uses magnetic fields to take images of the body.
  • PET scan — usually combined with a CAT scan, this takes a picture of your organs and tissues.
  • Ultrasound — this takes a picture of your internal organs using sound waves.
  • X-ray — the doctor uses this to take pictures inside your body, you first swallow a drink containing barium, which creates clearer images of the GI tract.

Treatments for gastrointestinal (GI) carcinoid tumors

The treatment depends on several things, including:

  • The tumor's size and location in your body
  • Whether the tumor has spread
  • Severity of your symptoms
  • Any other serious medical conditions

Depending on these factors, common treatments include:

  • Surgery — surgical removal is the ideal treatment for tumors that haven't spread; in some cases, doctors can't remove the entire tumor but can reduce its size.
  • Hormone Therapy — if surgery doesn't work, your doctor might try injections of a synthetic hormone called octreotide to slow the growth of the tumor.
  • Chemotherapy — these anti-cancer drugs kill cancer cells; chemotherapy is used if the tumor has spread or other treatments aren't working.
  • Radiation — radiation uses high-energy waves to kill the cancer cells; it doesn't work as well at fighting GI tumors, but it can treat severe pain.

Recovery from gastrointestinal (GI) carcinoid tumors

After treatment, you'll see your doctor regularly to make sure that the tumor doesn't return. Expect regular medical tests and physical exams to check that you're healthy.

Some tumors are slow-growing and can remain unseen for a long time, so it's important to let your doctor know if you have any new signs or symptoms after you recover from a digestive tract tumor.

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