The pancreas contains two main types of cells:
- Exocrine cells that produce digestive juices
- Endocrine cells that produce hormones
Adenocarcinoma starts in exocrine cells and accounts for 95 percent of pancreatic cancers. It occurs in the lining of the pancreatic ducts.
Islet cell carcinoma involves endocrine cells. Most islet cell carcinomas are malignant, but insulin-producing islet cell tumors are often benign (non-cancerous). Islet cell tumors can be:
- Functional and produce abnormally high amounts of hormones
- Non-functional and produce no hormones
Pancreaticoblastoma is very rare. This type of pancreatic cancer is found mostly in young children. Isolated sarcomas and lymphomas can also occur in the pancreas. These are very rare.
Pseudopapillary neoplasms are mostly found in women in their teens and 20s. Patients can present with pain, jaundice (yellowing), weight loss or a mass. These cancers mainly originate in the head of the pancreas. Resection of the tumor is often curative.
Ampullary cancer is a rare type of exocrine tumor that begins where the bile duct from the liver and the pancreatic duct join with the small intestine. Since it causes jaundice, yellowing of the skin and eyes, it may be found earlier than other types of pancreatic cancer and therefore has a better outcome.
There are several very rare types of pancreatic cancers, including:
- Adenosquamous carcinoma
- Squamous cell carcinoma
Some neuroendocrine tumors that can occur in the pancreas can be either benign or malignant:
- Insulinoma is a rare pancreatic tumor that secretes insulin, the hormone that lowers glucose levels in the blood.
- Gastrinoma is a tumor that secretes above-average levels of gastrin, a hormone that stimulates the stomach to secrete acids and enzymes. Gastrinoma can also cause stomach ulcers and can spread to the liver.
- Glucagonoma is a tumor that secretes glucagon, a hormone that raises levels of glucose in the blood, often leading to a characteristic rash.