The pancreas is a gland, about six inches long, located in the abdomen that is surrounded by the stomach, small intestine, liver, spleen and gallbladder.
The pancreas is both an exocrine gland and endocrine gland:
Exocrine cells of the pancreas produce enzymes that help with digestion. The endocrine cells of the pancreas produce hormones, which are substances that control or regulate many specific functions in the body. The two main pancreatic hormones are insulin and glucagon. Insulin lowers blood sugar levels and glucagon raises blood sugar levels. Together, these two main hormones work to maintain the proper level of sugar in the blood.
Exocrine Tumors: Pancreatic cancer begins when abnormal cells within the pancreas grow uncontrollably and form a tumor. More than 95% of pancreatic cancers are classified as exocrine tumors and more than 90% of these tumors are adenocarcinomas, where the cancer begins in the cells lining the pancreatic duct.
Rare forms of pancreatic cancers include:
- Acinar Cell Carcinoma, which overproduces enzymes to digest fats
- Intraductal Papillary-Mucinous Neoplasm, which is a cystic tumor usually located in the main pancreatic duct or in side branches of the duct
- Mucinous Cystadenocarcinoma, which is a cystic tumor usually located in the tail of the pancreas that is filled with a thick fluid called mucin
Endocrine Tumors: Pancreatic neuroendocrine tumors (PNETs) account for less that 5% of all pancreatic cancers. They arise from the hormone producing cells in the pancreas called islet cells. PNETs are functional, meaning they produce hormones, or nonfunctional, producing no hormones. Most PNETs are nonfunctional and cancerous.