What are Pancreatic Cysts?

Pancreatic cysts are collections (pools) of fluid within the head, body, or tail of the pancreas. Some pancreatic cysts are true cysts, that is, they are lined by a special layer of cells that are responsible for secreting fluid into the cysts. Other cysts are pseudocysts and do not contain specialized lining cells. Pancreatic cysts can range from several millimeters to several centimeters in size. Many pancreatic cysts are benign with no symptoms, but some cysts are cancerous or preecancerous. (Precancerous cysts are benign cysts that have the potential to become cancerous.)

Symptoms of Pancreatic Cysts

The symptoms of pancreatic cysts depend on their size and location. Small (less than two cm) cysts usually cause no symptoms. Large pancreatic cysts can cause abdominal pain and back pain presumably by putting pressure on surrounding tissues and nerves. Large cysts in the head of the pancreas also may cause jaundice (yellowing of the skin and eyes with darkening of color) due to obstruction of the common duct. Obstruction causes bile to back up and forces the chemical that produces bilirubin back into the bloodstream.

On rare occasions, acute pancreatitis can cause the formation of large pseudocysts that can compress the stomach or the duodenum leading to obstruction of flow within the intestines, abdominal pain, and vomiting. These cysts also may become infected and lead to fever, chills, and sepsis.

What are the Different Types of Pancreatic Cysts?

There are three common types of pancreatic cysts:

Pseudocysts: These are cysts that result from pancreatic inflammation (pancreatitis). They usually resolve on their own without treatment.

Serous cysts: These too are benign cysts and usually do not need treatment unless they grow large enough to cause symptoms.

Mucinous cysts: These cysts can be malignant at the time of diagnosis or may become malignant at a later time. Thus, they should be removed surgically if the patient is a good surgical candidate. Generally, larger cysts are more likely to be malignant or pre-malignant than smaller cysts.

There are characteristics of cysts on the CAT scan and ultrasound that help doctors determine a cyst's malignant potential. Sometimes, endoscopic ultrasound is necessary to adequately evaluate a cyst.