Nonfunctional and functional pNETs

Although nonfunctional pNETs can grow for a long time without causing signs or symptoms, the size of the tumor may cause:

• Diarrhea
• Indigestion
• A lump in the abdomen
• Pain in the abdomen or back
• Jaundice (yellowing of the skin and whites of the eye) if a bile duct is blocked

Functional pNETs can overproduce and release large amounts of these hormones into the bloodstream, depending on the endocrine cell of origin:

Insulin: lowers the levels of sugar in the blood
Glucagon: increases the levels of sugar in the blood
Gastrin: gives a signal to the stomach to produce more stomach acid
Vasoactive intestinal peptide (VIP): helps control water, salt, enzyme, and gastric acid secretions in the body. It also plays a role in the relaxation of smooth muscle in the digestive tract, heart, and blood vessels
Somatostatin: helps regulate other hormones in the body

When a pNET releases hormones, it may also be called:

• Insulinoma
• Glucagonoma
• Gastrinoma
• VIPoma
• Somatostatinoma