Pancreatic cancer can occur in several types of cells, each of which performs a unique function. Cancers in exocrine and endocrine cells are different from each other in most aspects of the disease, including its symptoms, risk factors, diagnostic methods and treatment processes. It is important for physicians to identify the exact type of cells that are cancerous. The following are pancreatic cancer cell types:

• Exocrine. Exocrine cells produce enzymes, which are transported through ducts to the digestive system, where they break down food. Most pancreatic cancers are exocrine cancers, and these cancers are further divided by the types of cells in which they occur. About 95 percent of exocrine pancreatic cancers are adenocarcinomas. More uncommon types of exocrine cancer include mucinous cystadenocarcinomas, acinar cell carcinomas, adenosquamous carcinomas, squamous cell carcinomas and large cell carcinomas. The exocrine cells may also develop benign cystoadenomas.
  
  
• Endocrine. Endocrine cells of the pancreas produce hormones, including insulin and glucagon, which control blood sugar. Most of the tumors of these cells are benign, and malignancy is rarer in the endocrine cells of the pancreas than in the exocrine cells. Endocrine pancreatic cancer can cause overproduction of insulin or glucagon, resulting in problems with the body’s production and storage of energy from blood sugar. Cancers of this cell type are called islet cell carcinomas or endocrine tumors. Cancer within insulin-producing cells is called insulinoma. Cancer within glucagon producing cells is called glucagonoma. A small percentage of pancreatic cancers occur in the endocrine cells.
  
  
• Ampulla of Vater. The structure where the bile and pancreatic ducts empty into the upper part of the small intestine, or duodenum. Cancers in this region are called ampullary cancer or carcinoma of the ampulla of Vater. Ampullary cancer may block the bile duct and this is one of the few pancreatic cancers that produces early symptoms. Jaundice is an early sign of this cancer (and a late-stage sign of other pancreatic cancers). Because of this symptom, ampullary cancer it is often detected in the early stages, resulting in a better prognosis than other pancreatic cancers.