Magnetic Resonance Cholangiopancreatography with Secretin Stimulation in the Diagnosis of Intraductal Papillary Mucinous Neoplasm: A Paradigmatic Case Report

Context. One of the characteristic findings of intraductal papillary mucinous neoplasms (IPMN) is the presence of a direct communication between the lesion and the ductal pancreatic system and when magnetic resonance cholangiopancreatography (MRCP) shows uncertain findings, it is useful to perform a MRCP after secretin stimulation (MRCP-S) which provides a better visualization of the ductal system. Case Report. We present a case of 51-year-old man in whom, during a CT follow-up for a renal tumour, was found a cystic lesion of the pancreas. To better evaluate the lesion and its suspected communication with the pancreatic system, MR with gadolinium and MRCP and MRCP-S were performed. With the MRCP and MRI it was not possible to identify a clear communication between the cystic lesion and the ductal system. MRCP-S showed an increase in signal intensity of the lesion and its communication with the ductal system, allowing us to classify the cystic lesion as a main duct in intraductal papillary mucinous neoplasm. The patient underwent a surgical duodenal pancreatectomy. The histological result of the specimen confirmed the diagnosis of adenocarcinoma IPMN. Conclusion. In this case MRCP-S has allowed a clearer identification of the cystic lesion allowing a correct diagnosis and treatment. 1. Introduction During the past year an increase of cystic pancreatic lesions, due to the widespread use of cross-sectional imaging, was observed. A correct assessment of pancreatic cystic lesions plays an important role as the different degree of malignancy of the lesions and therefore their different medical treatment. Imaging plays a fundamental role in the correct diagnosis and classification of pancreatic cystic lesions. A good evaluation of the morphology of the ductal system permits visualizing the signs of a chronic pancreatitis and its related pseudocysts, which are the most common cause of pancreatic cystic lesion. In the evaluation of the pancreatic cystic neoplasms (mucinous cystadenoma, serous cystadenoma, and IPMN with different degree of atypia) it is important to have a clear view of the relationship that the lesion has with the ductal system, since the presence of a communication between the lesion and the ductal system is a typical finding of intraductal papillary mucinous neoplasms (IPMNs). The gold standard for the study of the ductal system is magnetic resonance cholangiopancreatography (MRCP), yet sometimes it can not provide unique information on the relationship of the cystic lesions with the ductal system. MRCP with secretin stimulation provides a