Review of guidelines for pancreatic cysts

Pancreatic cysts are initially not closely associated with pancreatic cancer: on the contrary, the association with the disease is low. However, there are significant concerns about malignant pancreatic tumors, mainly due to the high rates of surgical morbidity and the uncertain prognosis of tumors after surgery. Due to the increasing capacity of imaging methods, the incidence of pancreatic cysts has increased over the decades. The dilemma is: How do you deal with these cysts in practice?

Diagnostic work and management of pancreatic cysts is based on guidelines published by major specialist societies. It is a way of balancing the risks and benefits between surgery and follow-up of cystic pancreatic lesions with the potential for malignancy. A review published in JAMA Surgation compares the five major societies that have published guidelines on the topic: the American Gastroenterological Association (AGA), the American College of Gastroenterology (ACG), the American College of Radiology (ACR), and the evidence-based European guidelines. and the International Institute. Pancreatic Diseases Association (IAP).

For the review, a comparison was made of the previously published guidelines by the above-mentioned associations, with their respective recommendations. Each guiding principle has its own peculiarity, and therefore it cannot be compared directly in all aspects.

Classification of pancreatic cysts

Cystic lesions of the pancreas can be roughly divided into two categories: mucin-producing and non-mucin-producing. Among those that do not produce mucin, cystic neuroendocrine tumors and papillary neoplasms are those that need more attention in follow-up. This is because serous cystic adenomas have a malignancy rate of less than 1%, in addition, pancreatic pseudocysts are inflammatory processes that do not develop into metastasis.

On the other hand, when dealing with mucin-producing tumors, it is the intracytoplasmic mucin-producing tumors that are characterized by the greatest variability in behaviour. It can be classified as a major duct or a secondary duct. Because of their malignant potential, mucin-producing cystic tumors should also be monitored.

Even with all the advances in CT, both MRI and CT have imperfect diagnostic accuracy. Thus, in some cases, the use of ultrasound endoscopy is necessary. This, in addition to being able to determine the type of lesion by ultrasound appearance, can also, in cases of doubt, be performed for biochemical and/or cytological analysis, which (significantly) increases the throughput of the method.

Guidelines and recommendations

The recommendations made by the guidelines have a low level of evidence regarding aspects of follow-up, both preoperative and postoperative.

An interesting problem is that in most cases, even with the use of fine needle puncture, the degree of dysplasia present in the specimen cannot be reliably determined. In the analysis of some segments of the secondary duct IPMN, a high degree of dysplasia that was not suspected in the preoperative period was identified. The use of needles that allow samples to be collected for tissue dissection may alleviate this suspicion. However, many mosaic dysplasias may be present, which underestimates the sample’s representation.

The article published in JAMA Surgation concluded that because of the low level of evidence in recommendations, it is essential that a patient with a cystic lesion of the pancreas be followed up by a referral centre. In this way, it is possible for the behavior to be defined firmly, given the great variety of details in each case.

Look at the table below and learn more:

Community	Worrying results that may indicate surgery
AGA	Bag > 3.0 cm dilation of the main pancreatic duct cystic solid component Cytology with high-grade dysplasia or invasive carcinoma
ACG	Recently appeared diabetes Secondary cystic jaundice Acute pancreatitis secondary to cystic AC 19-9 high Cyst growth > 3 mm/year Mural/hard component in the bag Main channel dilation >5mm Partial dilation of the main channel in the suspected main channel IPMN IPMN or myxoma > 3.0 cm Cytology with high-grade dysplasia or invasive carcinoma
ACR	Signs of anxiety: Bag larger than 3.0 cm in diameter Thicker/improved cyst wall Wall knot without contrast absorption Main channel > 7mm secondary jaundice of the cyst Mural knots capture contrast Main channel >10mm in the absence of obstruction Cytology with high-grade or invasive dysplasia
European	Relative indications for surgery: Growth rate > 5 mm/year CA 19-9 > 37 units/ml Main channel 5-9 mm Bag diameter > 4 cm New diabetes mellitus caused by IPMN Parietal ganglion absorption <5 mm Cytology with high-grade dysplasia or invasive carcinoma solid mass secondary jaundice of the cyst Contrast capture wall knot >5mm Main channel > 10mm
In-app purchase	IPMN main output with: Main channel > 10mm jaundice Wall knot > 5 mm Cytology with high-grade dysplasia or invasive carcinoma IPMN secondary duct and thoracic <2.9 cm with: Main channel >10mm or main channel involvement jaundice Wall knot > 5 mm Cytology with high-grade dysplasia or invasive carcinoma

to take to practice

Follow-up for cystic lesions of the pancreas requires constant attention and update by the assisting professional. Due to the nuances in each case, this follow-up should be dynamic, since the same parameter analyzed may refer to surgery in one patient and not in another. Knowing how to choose the best diagnostic method, and even the ideal time to indicate surgery, usually requires an interdisciplinary discussion between the treatment center’s different disciplines.