Pancreatic cancer is grouped based on the type of cells where the cancer begins. The two main categories are exocrine cancers and neuroendocrine cancers. These types differ in how they grow, how they are treated, and their outlook.
Exocrine cancers develop in cells that produce digestive enzymes. They account for more than 95% of pancreatic cancer cases. The most common form is pancreatic adenocarcinoma, which begins in the ducts of the pancreas.
Other rare exocrine cancers include acinar cell carcinoma, adenosquamous carcinoma, squamous cell carcinoma, and colloid carcinoma.
This is the most common type of pancreatic cancer, representing over 90% of diagnoses. It forms in the lining of the pancreatic ducts and is often the type referred to when people discuss pancreatic cancer.
Neuroendocrine tumors develop from hormone-producing cells in the pancreas. They are rare — typically less than 5% of pancreatic cancers — and often grow more slowly than exocrine cancers.
Some NETs produce hormones that cause symptoms, while others do not.
Certain cysts or lesions in the pancreas can develop into cancer over time. Examples include intraductal papillary mucinous neoplasms (IPMNs). Doctors may monitor or remove these to reduce cancer risk.