of the pancreas
Cysts are cavities that form in tissue and are surrounded by a type of capsule. They may consist of one or more chambers and be filled with tissue fluid, blood or pus.
Cystic changes in the pancreas have been increasing in importance recently and can have various causes. They are often discovered as incidental findings due to our nowadays better imaging (CT, MRI, endosonography) during clarification of other diseases. Overall, they occur more frequently with increasing age.
Genuine cystic neoplasms (tumors) must be distinguished from so-called pseudocysts, which can develop after acute or chronic pancreatitis. Cystic tumors of the pancreas are usually benign, but depending on which cystic change is present, they have a risk of developing into a malignant (malignant) tumor in the long term, similar to the polyps in the colon (so-called polyp-adenoma-carcinoma sequence). In contrast to cysts in other organs such as the liver and kidneys, cystic changes in the pancreas should undergo specialized evaluation to assess the risk of degeneration into a malignant tumor. The vast majority of these cystic changes can be controlled at regular intervals, but in the other part surgery is necessary.
What are the signs of the disease?
In most cases (80% or more), the cystic changes do not cause any symptoms. However, if the cysts reach a certain size and/or press on neighboring structures such as the bile duct, they can cause symptoms such as a feeling of pressure in the upper abdomen, bloating, pain or jaundice (icterus). New-onset diabetes mellitus and unwanted weight loss should always be investigated further. In this context, it may be a sign of malignancy.
Computed tomography (CT) of the abdomen and magnetic resonance imaging (MRI) with additional imaging of the pancreas and bile ducts (MRCP: magnetic resonance cholangiopancreatography) are generally used for diagnosis. Endosonography (ultrasound "from the inside" as part of a gastroscopy) also has its place in cystic tumors and can yield groundbreaking findings. With regard to the so-called malignant degeneration (development and presence of cancer), tumor markers in the blood (CA 19-9, CEA) or in the secretion are determined by puncturing the cysts during endosonography. Puncturing the cyst is technically demanding and not always successful. This procedure is also associated with certain risks, such as triggering acute pancreatitis. The decision to perform a puncture must therefore be made after careful consideration of the risk-benefit ratio. The main aim of the puncture is to analyze the fluid for altered cells.
The treatment of cystic tumors
With the help of the patient's medical history, gender, age and imaging techniques (CT, MRI, endosonography), pancreas specialists can assign affected patients to one of the different types of cystic pancreatic tumours. The recommended therapy is based on this. According to current studies, changes that are smaller than about 2 centimetres and do not have any risk factors can be checked at regular intervals. For the other changes, surgery is necessary to prevent the development of pancreatic cancer or to remove it at the earliest possible stage. Thus, the prognosis of these changes is very good overall.
The four most common cystic tumours of the pancreas
Serous cystadenoma / serous cystic neoplasia (SCN)
Serous cystic tumours of the pancreas form a so-called serous (thin) secretion. They are more common in women and in patients over the age of 60. In very rare cases (less than 3 per cent), a malignant tumour (serous cystadenocarcinoma) is already present. It is the cystic tumour with the lowest risk of degeneration and can basically be controlled with imaging at regular intervals. It should be surgically removed especially if symptoms occur, if it increases in size or if it exceeds 3 to 4 centimetres in size.
Mucinous cystadenoma / mucinous cystic neoplasia (MCN)
Mucinous cystic tumours, in contrast to serous changes, form a so-called mucinous (viscous and mucous) secretion. Women are affected significantly more often and the average age is younger than for other cystic tumours, at 40 to 50 years. About 90 per cent of the tumours occur in the body or tail area of the pancreas. The mucinous cystadenomas (benign tumours) show a transition to borderline tumours (change towards cancer) or to mucinous cystadenocarcinomas (malignant tumours) and should therefore always be removed. A so-called oncological resection - with sufficient safety margin and taking along associated lymph nodes - is performed to avoid recurrences of tumours. Since the tumour often occurs in the tail region of the pancreas, pancreatic left resection is the most common operation here, with or without simultaneous removal of the spleen.
Intraductal papillary mucinous neoplasia (IPMN)
Intraductal papillary-mucinous neoplasms originate from the pancreatic ductal epithelium, i.e. the mucous membrane in the ductal system of the pancreas. In contrast to the other cystic changes, they have a connection to the ductal system of the pancreas. These tumours occur most frequently between the ages of 60 and 70, and about 80 per cent of IPMNs occur in the head of the pancreas. However, this tumour very often shows multifocal growth (occurring at multiple sites), with up to ten or even more localisations.
There is a further subdivision of these changes in terms of origin into main duct IPMN (originating from the main duct), branch duct IPMN (originating from the side ducts) or mixed types in which both main and side ducts are affected.
As with mucinous tumours (MCNs), there is a progression of IPMNs from adenoma to borderline tumour to carcinoma. Tumours originating from the main duct (MD-IPMN) have a high risk of malignant degeneration and should be surgically removed. As with MCNs, an oncological resection should be performed with a sufficient safety margin and taking associated lymph nodes with it.
IPMNs originating from the lateral ducts (BD-IPMN) show a lower risk of degeneration. Smaller cysts that do not cause any symptoms and do not show any risk factors on imaging can be checked at regular intervals. In case of symptoms, an increase in size or abnormalities (so-called worrying characteristics) on imaging, surgical therapy should be performed.
Solid-pseudopapillary neoplasia (SPN)
These cystic changes are very rare and occur mainly in young women. They are regularly malignant or even show metastases. Surgical oncological resection is attempted.