Pancreatic cancer begins when abnormal cells within the pancreas grow out of control and form a tumor. There are two types of cells in the pancreas, the exocrine cells and endocrine cells. These cells also have different functions.
More than 95% of pancreatic cancers are classified as exocrine tumors. These tumors start in the exocrine cells that make pancreatic enzymes that help in digestion. Within this category, the vast majority of tumors are adenocarcinomas. The following table describes the different types of pancreatic exocrine tumors. Click here to learn about types of exocrine tumors in the pancreas.
Pancreatic neuroendocrine tumors (pancreatic NETs or PNETs) account for less than 5% of all pancreatic tumors. They may be benign or malignant and they tend to grow slower than exocrine tumors. They develop from the abnormal growth of endocrine (hormone-producing) cells in the pancreas called islet cells. This is why these tumors are sometimes referred to as “islet cell tumors.”
Pancreatic neuroendocrine tumors are either functional (produce hormones) or nonfunctional (produce no hormones). The majority of PNETs are nonfunctional tumors. Click here to learn about types of endocrine tumors in the pancreas.