Pancreatic Neuroendocrine Tumor
A pancreatic neuroendocrine tumor (PNET) is a growth that arises from the hormone-producing (endocrine) cells of the pancreas. These tumors can be functioning—meaning they produce excess hormones that cause specific symptoms—or non-functioning, in which case symptoms often appear only after the tumor grows large. PNETs are typically slower-growing than the more common pancreatic adenocarcinoma, but some can be aggressive or spread to other organs.
What is it?
A pancreatic neuroendocrine tumor develops from the pancreatic islet cells that produce hormones such as insulin and glucagon. Functioning PNETs produce excess hormones and can lead to specific symptoms like low blood sugar, stomach ulcers, or severe diarrhea. Non-functioning tumors may not cause symptoms until they grow or press on nearby structures.
Imaging helps determine whether the tumor is functioning or non-functioning, how large it is, and whether it has spread. MRI and CT scans evaluate tumor size and involvement of nearby tissues, while specialized PET scans (like DOTATATE PET) help detect neuroendocrine activity throughout the body.
Important to Know
PNETs vary in their behavior—some are slow-growing and may be monitored safely, while others can spread to the liver or lymph nodes and require more urgent treatment. Treatment decisions depend on tumor size, hormone activity, and whether the tumor has spread.
Red flag symptoms include severe abdominal pain, sudden jaundice, persistent diarrhea, fainting or confusion from low blood sugar, or unexplained weight loss. These symptoms may indicate a functioning tumor or tumor growth requiring rapid evaluation. Follow-up imaging is important for monitoring treatment response and long-term outcomes.