Types of pancreatic cancer

There are 2 main types of pancreatic cancer. They are named after the cell types in which the cancer first develops: 

• Exocrine pancreatic cancers are also known as exocrine tumours. This type of cancer develops in exocrine cells and is the most common type of pancreatic cancer, accounting for more than 95%^[1] of all cases. Most of these are a type of cancer called adenocarcinoma, which starts in the cells lining the pancreatic duct.^[2] Other types include adenosquamous carcinoma and undifferentiated carcinoma. 
• Endocrine pancreatic cancers are also known as pancreatic neuroendocrine tumours (NETs), or islet cell tumours. These are much less common than exocrine tumours. This type of cancer forms from tumours that develop in endocrine cells, but the original tumours are not always malignant. The 2 types of these tumours are 
• functioning tumours – these tumours produce hormones, based on the type of cells they develop in – for example, if they grow from insulin-producing cells, the tumour will produce insulin 
• non-functioning – these tumours do not produce hormones and are more likely to be malignant compared to functioning tumours.  

Exocrine and endocrine cancers have different causes, risk factors, symptoms, diagnostic methods, treatments and outlooks (prognosis). 

For further information on neuroendocrine tumours, see neuroendocrine tumours.