Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
There are two major types of pancreatic cysts; pseudocysts (inflammatory cysts) and true cysts (non-inflammatory cysts). Inflammatory cysts are benign, whereas non-inflammatory cysts can be benign, precancerous, or cancerous.
Most of the inflammatory cysts of the pancreas are pancreatic pseudocysts. Pseudocysts of the pancreas result from pancreatitis (inflammation of the pancreas). The common causes of pancreatitis include alcoholism, gallstones, trauma, and surgery. The fluid inside the pseudocysts represents liquefied dead pancreatic tissue, cells of inflammation, and a high concentration of digestive enzymes that are present in pancreatic exocrine secretions. (Most pseudocysts have connections with the pancreatic ducts.) Most pseudocysts caused by acute pancreatitis resolve spontaneously (without treatment) within several weeks. Pseudocysts that need treatment are those that persist beyond six weeks and are causing symptoms such as pain, obstruction of the stomach or duodenum, or have become infected.
Serous cyst adenomas: These cysts are mostly benign and commonly occur in
middle-aged women. They usually are located in the body or tail of the pancreas. Typically they are small and cause no symptoms although rarely they may cause abdominal pain.
Mucinous cyst adenomas: Thirty percent of these cysts contain cancer, and those that do not contain cancer are considered precancerous. They also commonly occur in middle-aged women and are usually located in the body or tail of the pancreas.
Intraductal papillary mucinous neoplasm (IPMN): These cysts have a high likelihood of being or becoming cancerous. At the time of diagnosis, there is a 40% to 50% chance of the cyst already being cancerous. These cysts are more common in middle-aged men and are more commonly located in the head of the pancreas. The cysts typically produce large amounts of mucous which sometimes can be seen draining out of the papilla of Vater at the time of endoscopic retrograde cholangio-pancreatography (ERCP), a test that visualizes the ampulla of Vater and the pancreatic duct. These cysts can cause abdominal pain, jaundice, and pancreatitis. Increased risk for cancer occurs with older age of the patient, presence of symptoms, involvement of the main pancreatic duct, dilation of the main pancreatic duct over 10 mm, the presence of nodules in the wall of the duodenum, and size over 3 cm for side-branch IPMN.
Solid pseudopapillary tumor of the pancreas: These are rare tumors that have both solid and cystic components and are found mainly in young Asian and black women. They may reach a large size and can become malignant. Prognosis is excellent after complete surgical resection of these tumors.