The role of endoscopic ultrasound in the management of intraductal papillary mucinous neoplasms.

ABSTRACT

As the use of cross-sectional imaging increases so does the incidence of asymptomatic pancreatic cysts. Pancreatic neoplastic cysts can be broadly grouped into mucinous lesions and solid pseudopapillary neoplasms, which have malignant potential and serous lesions, which have negligible malignant potential. Non-neoplastic pancreatic cysts such as pseudocysts are not associated with malignant potential. It is important to identify those mucinous lesions with the highest potential of malignancy as identifying these lesions may allow prevention or early treatment of pancreatic carcinoma. The preoperative diagnosis of these cysts remains challenging with imaging alone often proving inadequate at making the diagnosis. Endoscopic ultrasound (EUS) can assess the morphology of cysts including identification of malignant characteristics of cysts as well as allowing aspiration of cyst fluid, which can be analysed for cytology, mucin, tumour markers, amylase and DNA analysis. Intraductal papillary mucinous neoplasms (IPMNs) can be subdivided into main duct IPMNs (MD-IPMN), branch duct IPMNs (BD-IPMN) and mixed type IPMNs which have feature of both the aforementioned. MD-IPMNs have the highest malignant potential and are often easier to identify on cross-sectional imaging due to the involvement of the main pancreatic duct. BD-IPMNs however can be difficult to distinguish from non-mucinous lesions such as pseudocysts, serous cyst adenomas and other benign cysts such as duplication cysts and in this group of lesions EUS is a valuable tool both to aid diagnosis and to identify BD-IPMNs, which should be considered for surgical resection.