Symptoms are caused by the hormone the tumor is producing. For example, an insulinoma may produce too much insulin, leading to very low blood sugar levels.

Symptoms can include:

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

Tests may vary depending upon the symptoms. The following tests may be performed:

• Abdominal CT scan
• Abdominal ultrasound
• Endoscopic ultrasound
• Fasting glucose level
• Gastrin level
• Gucose tolerance test
• Intraductal endoscopic ultrasound
• MRI of abdomen
• Sampling the vein drainage of segments of the pancreas
• Secretin stimulation test for pancreas
• Serum glucagon level
• Serum insulin C-peptide
• Serum insulin level

Occasionally, surgery is needed to diagnose and treat this condition. During this procedure, the surgeon feels the pancreas and may use ultrasound probes.