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 and produce no symptoms, but some cysts are cancerous or precancerous. (Precancerous cysts are benign cysts that have the potential to become cancerous.)
What are the 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 urine color) due to obstruction of the common duct. Obstruction causes bile to back up and forces bilirubin (the chemical that produces jaundice) back into the bloodstream.
What are the different causes and types of pancreatic cysts?
There are two major types of pancreatic cysts; inflammatory cysts and non-inflammatory cysts. Inflammatory cysts are benign, whereas non-inflammatory cysts can be benign, precancerous, or cancerous.
- 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. They rarely 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 are more common 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%-50% chance of already being cancerous. These cysts are more common among middle-aged men and are more commonly located in the head of the pancreas. These cysts can cause abdominal pain, jaundice and pancreatitis.
- Solid pseudopapillary tumor of the pancreas: These are rare tumors found mainly in young Asian and black females. They may reach a large size, and can become malignant. Prognosis is excellent after complete surgical resection of these tumors.
How are pancreatic cysts diagnosed?
Since the majority of pancreatic cysts are small and produce no symptoms, they often are discovered incidentally when abdominal scans (ultrasound,CT scan, or MRI) are performed to investigate unrelated symptoms. Unfortunately, ultrasound, CT, and MRI scans cannot reliably distinguish benign cysts (cysts that usually need no treatment) from precancerous and cancerous cysts (cysts that usually require surgical removal).
Endoscopic ultrasound(EUS) is becoming increasingly useful in determining whether a pancreatic cyst is benign, precancerous, or cancerous. During EUS, an endoscope with a small ultrasound transducer on its tip is inserted through the mouth, esophagus, and stomach into the duodenum. From this location very close to the pancreas, liver, and gallbladder, accurate and detailed images can be obtained of the liver, pancreas and the gallbladder.
What is the treatment for pancreatic cysts?
The most important aspect of management of pancreatic cysts is the determination of whether a cyst is benign (and usually needs no treatment) or if it is cancerous and must be removed.
The second most important aspect of management is to determine whether a patient with a precancerous or cancerous pancreatic cyst is a suitable surgical candidate. In medical centers experienced in performing pancreas surgery, surgical removal of precancerous or cancerous cysts has a high rate of cure.
There are not yet standard recommendations for managing pancreatic cysts. Different medical centers have adopted different approaches to diagnosis and treatment. Management decisions must be individualized for each patient after discussions with a doctor familiar with the patient’s health status.