The short answer
About 95 percent of pancreatic cancers start in exocrine cells, most often as adenocarcinoma. The rest start in neuroendocrine cells. The two types have very different causes, risk factors, treatments, and outlooks.
The pancreas has two main cell types: exocrine cells and neuroendocrine (endocrine) cells.
About 95 percent of pancreatic cancers are exocrine tumors, most often adenocarcinoma.
Neuroendocrine tumors, sometimes called islet cell tumors, make up a small share of pancreatic cancers.
Neuroendocrine tumors are much less common than exocrine cancers and are treated differently.
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The whole article, with every detail and caution.
This page explains the two main types of pancreatic cancer and why the difference matters.
The simple version
The pancreas has two main jobs, and two main kinds of cells. Exocrine cells make digestive enzymes. Endocrine cells, also called neuroendocrine cells, make hormones like insulin. Cancer can start in either kind. The two types have very different causes, risk factors, treatments, and outlooks.
Exocrine pancreatic cancer
Most pancreatic cancers start in exocrine cells. The most common kind is adenocarcinoma, which makes up about 90 percent of pancreatic cancers. When people say "pancreatic cancer" without naming a type, they usually mean this one. Exocrine cancer is usually found at an advanced stage.
Neuroendocrine pancreatic tumors
A smaller share of these cancers start in the hormone-making cells. They are sometimes called islet cell tumors. Another name is pancreatic neuroendocrine tumors, or PNETs. These tumors:
- Have a better prognosis than exocrine pancreatic cancer. Some are small and slow-growing.
- Can be "functional." That means they make extra hormones that cause symptoms. Too much insulin, for example, can push blood sugar too low.
- Can also be "non-functional." These do not make extra hormones.
- Are treated in their own way. The outlook varies by tumor type and stage.
In short: exocrine cancer, most often adenocarcinoma, is the usual kind. Neuroendocrine tumors are much less common, and they have different causes, risk factors, treatments, and outlooks.
Why the distinction matters for treatment
These two types come from different cells and are treated in different ways. Treatment for neuroendocrine tumors can include surgery, hormone therapy (somatostatin analogs can help slow the growth of some types and control symptoms), chemotherapy, radiation, targeted therapy, or, for some small slow-growing tumors, close watching. Ask your care team how your tumor type affects your plan.
Sources
Common questions
What does exocrine and neuroendocrine mean?
Exocrine cells in the pancreas make enzymes that help digest food. Neuroendocrine cells, also called islet cells, make hormones like insulin. Cancer can start in either type of cell, and the two behave very differently.
Which type is more common?
About 95 percent of pancreatic cancers are exocrine tumors, most often a type called adenocarcinoma. When people say 'pancreatic cancer' without specifying, they usually mean this type.
Are neuroendocrine pancreatic tumors less serious?
Neuroendocrine tumors have a better prognosis (outlook) than exocrine pancreatic cancer, and some are small and slow-growing. Some produce extra hormones that cause symptoms. Outlook varies by tumor type and stage, so the distinction matters.
How do I know which type I have?
A biopsy and pathology review determine the exact cell type. Ask your care team directly whether your cancer is exocrine or neuroendocrine, since this shapes your whole treatment plan.
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Last updated: 2026-10-16Next planned review: 2027-08-03
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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