A pancreatic islet cell tumor is an uncommon tumor of the pancreas that arises from a cell in the pancreas, referred to as the islet cell. Normally, islet cells produce insulin and other hormones, and islet cell tumors can also produce hormones.

In the normal pancreas, cells called islet cells produce hormones that regulate a variety of bodily functions, such as blood sugar level and the production of stomach acid.

Tumors that arise from islet cells of the pancreas can also produce a variety of hormones, though some do not. Although islet cells produce many different hormones, most tumors secrete only one specific hormone that leads to specific symptoms. Pancreatic islet cell tumors can be benign or malignant (cancerous).

Islet cell tumors include insulinomas, glucagonomas, and gastrinomas (Zollinger-Ellison syndrome). A family history of multiple endocrine neoplasia, type I (MEN I) is a risk factor for the development of islet cell tumors.

• Sweating
• Tremor
• Rapid heart rate
• Anxiety
• Hunger
• Dizziness
• Headache
• Clouding of vision
• Confusion
• Behavioral changes
• Convulsions
• Loss of consciousness
• Skin rash that migrates on the face, abdomen, perineum, buttocks, or lower extremities
  • May be crusty and scaly
  • May have raised lesions filled with clear fluid or pus
• Inflamed mouth and tongue
• Weight loss
• Weight gain (unintentional)
• Peptic ulcer pain
• Vomiting blood
• Diarrhea
• Abdominal pain

Note: The symptoms depend upon the type of tumor and the hormone produced.

The type of tests performed may vary depending upon the symptoms associated with the condition. The following tests may be performed:

• An abdominal CT scan  (sometimes the tumor may be too small to see with a CT scan)
• MRI of abdomen (MRI can sometimes see smaller tumors than those seen with a CT scan)
• Gucose tolerance test
• Fasting glucose level
• Serum insulin C-peptide
• Serum insulin level
• Gastrin level
• Secretin stimulation test for pancreas
• Fasting glucose level
• Serum glucagon level
• Abdominal ultrasound
• Endoscopic ultrasound
• Intraductal endoscopic ultrasound
• Sampling of the venous drainage of segments of the pancreas
• Occasionally, the diagnosis and treatment requires exploratory surgery, during which the surgeon feels the pancreas and may use ultrasound probes