Usefulness of Contrast-enhanced Harmonic Endoscopic Ultrasound (CH-EUS) for the Differentiation of the Pancreatic Cysts and for Guiding Endoscopic Ultrasound Guided Fine Needle Aspiration (EUS-FNA) From Murale Nodules.

Due to the increase use of cross-sectional imaging techniques for varied medical conditions more and more pancreatic cysts are incidentally found. Magnetic resonance imaging revealed a prevalence of incidental pancreatic cystic neoplasm (PCN) in adults between 2,4-49,1% and autopsy studies showed that half of the individuals had pancreatic cysts.

There is a great variety of pancreatic cysts, they are mainly divided in neoplastic or non-neoplastic (i.e pseudocyst). Pseudocysts appear after acute or chronic pancreatitis and represent only 20% of all pancreatic cysts.. PCN include a diverse group of pancreatic cysts including mucin-producing (Intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN)) and nonmucin-producing lesions (Serous cystadenoma (SCN), Solid pseudopapillary neoplasm(SPN) cystic neuroendocrine tumor(cNET)) with different morphology and progression to malignancy. SPN's,cNET are considered premalignant or malignant conditions and require surveillance or surgical resection. SCN instead are benign and surveillance is not necessary. Resection is considered only if symptoms are present.

The discrimination between the different cyst types is crucial for the therapeutic approach. Their morphology can be similar and sometimes it's a challenge to diagnose them.There are many tools but none is good enough to be used alone.

Contrast-enhanced harmonic endoscopic ultrasound using low mechanical index (0.12-0.4) is an additional test to assess the vascularization of the cystic wall and the septa and solid component for the differential diagnosis of PCN.

Our aim was to identify specific imaging characteristics using CH-EUS in order to increase the diagnostic accuracy for potential malignant pancreatic cysts.