Oncologist-approved cancer information from the American Society of Clinical Oncology
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Islet Cell Tumor

This section has been reviewed and approved by the Cancer.Net Editorial Board, 4/2013
Symptoms and Signs

ON THIS PAGE: You will find out more about body changes and other things that can signal a problem that may need medical care. To see other pages in this guide, use the colored boxes on the right side of your screen, or click “Next” at the bottom.

People with an islet cell tumor may experience the following symptoms or signs. Sometimes, people with an islet cell tumor do not show any of these symptoms. Or, these symptoms may be caused by a medical condition that is not a tumor. If you are concerned about a symptom or sign on this list, please talk with your doctor.       


  • Ulcers (from too much stomach acid)
  • Diarrhea


  • Hypoglycemia, which causes fatigue, nervousness and shakiness, dizziness or light-headedness, seizures, and fainting episodes
  • Confusion


  • Hyperglycemia, which causes frequent urination, increased thirst, and increased hunger
  • Rash that spreads on the face, abdomen, or lower extremities


  • Watery diarrhea
  • Too little potassium in the blood (can cause an irregular heartbeat, muscle cramping and weakness, and decreased reflexes)
  • Too little acid in the stomach (can cause digestive problems and poor absorption of vitamins and nutrients)
  • Flushing (redness in the face, neck, or chest)
  • Fatigue
  • Nausea


  • Type 2 diabetes (sometimes called adult-onset diabetes)
  • Gallstones
  • Steatorrhea (a condition where the body cannot absorb fat, causing oily and loose stools with a particularly bad odor)
  • Diarrhea
  • Weight loss
  • Too little hydrochloric acid in the stomach (can cause digestive problems and poor absorption of vitamins and nutrients)

Other symptoms

  • Abdominal pain
  • Jaundice (yellowing of the skin and whites of the eyes)
  • Vomiting blood
  • Sweating
  • Rapid heart rate
  • Anxiety
  • Headache
  • Convulsions
  • Loss of consciousness
  • Clouding of vision
  • Unexplained weight gain or loss
  • Inflamed mouth and tongue
  • A mass or lump in the abdomen

Your doctor will ask you questions about the symptoms you are experiencing to help find out the cause of the problem, called a diagnosis. This may include how long you’ve been experiencing the symptom(s) and how often.

If a tumor is diagnosed, relieving symptoms and side effects remains an important part of your care and treatment. This may also be called symptom management, palliative care, or supportive care. Be sure to talk with your health care team about symptoms you experience, including any new symptoms or a change in symptoms.

Choose “Next” (below, right) to continue reading this guide to learn about what tests and scans you may have to learn more about the cause of your symptoms. Or, use the colored boxes located on the right side of your screen to visit any section.

Last Updated: 
Tuesday, April 23, 2013

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