Endoscopic ultrasound in the diagnosis of pancreatic intraductal papillary mucinous neoplasms

Abstract

Pancreatic cystic lesions are increasingly recognised due to the widespread use of different imaging modalities. Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas represent a common, but also heterogeneous group of cystic tumors with a significant malignant potential. These neoplasms must be differentiated from other cystic tumors and properly classified into their different types, main-duct IPMNs vs branch-duct IPMNs. These types have a different malignant potential and therefore, different treatment strategies need to be implemented. Endoscopic ultrasound (EUS) offers the highest resolution of the pancreas and can aid in the differential diagnosis, classification and differentiation between benign and malignant tumors. The addition of EUS fine-needle aspiration can supply further information by obtaining fluid for cytology, measurement of tumor markers and perhaps DNA analysis. Novel techniques, such as the use of contrast and sophisticated equipment, like intraductal probes can provide information regarding malignant features and extent of these neoplasms. Thus, EUS is a valuable tool in the diagnosis and appropriate management of these tumors.

Keywords: Endoscopic ultrasound; Pancreatic intraductal papillary mucinous neoplasms.

Figure 1

Multilocular branch-duct intraductal papillary mucinous neoplasms in the uncinate process of the pancreas (communication with the pancreatic duct is just visible).

Figure 2

Branch-duct intraductal papillary mucinous neoplasms communicating with a non-dilated pancreatic duct.

Figure 3

Main-duct - intraductal papillary mucinous neoplasms with a mural nodule. This figure shows a dilated main pancreatic duct (short arrow), with a mural nodule within the duct (long arrow). This patient was found to have a main-duct - intraductal papillary mucinous neoplasms with an invasive adenocarcinoma.

Figure 4

Fine-needle aspiration of a branch-duct intraductal papillary mucinous neoplasms. Material obtained was mucinous (Papanikolaou staining) with low cellularity. Mucinous cells did not demonstrate nuclear atypia and expressed MUC5AC, but not MUC1 or MUC2 on immunostaining, findings consistent with a benign branch-duct intraductal papillary mucinous neoplasms.