Imagerie en coupes des tumeurs kystiques du pancréas

Cystic tumors of the pancreas were considered to be rare. Their radiologic diagnosis has been dominated by their distinction from postnecrotic and retention pseudocysts. Widespread use of cross-sectional imaging with high resolution CT and MRI has revealed their real prevalence. Their identification has become a common daily problem. These new imaging procedures have also enabled a better understanding of their potential for degeneration, a determining factor for treatment. According to recent clinical research studies, 30% of common ductal pancreatic adenocarcinomas would issue from the degeneration of previous benign intraductural papillary mucinous neoplasms (IPMN) lesions (which have now become the most frequently encountered cystic pancreatic tumor). IPMN involving the main pancreatic duct have a very high malignant potential; at five years, the estimated risk of degeneration is 50%. Theoretically treatment involves as complete as possible resection, with the main goal of avoiding total pancreatectomy and the subsequent serious nutritional and functional sequelae. This surgical treatment must be discussed with a multidisciplinary staff, considering each individual patient's life expectancy and surgical risk. The five-year risk of degeneration for IPMN limited to the secondary pancreatic ducts ranges from 5 to 10%. A five-year follow-up is thus indicated for these patients; surgical resection can be proposed if mural nodules develop. Unlike mucinous and, to a lesser extent, serous adenoma, lymphoepithelial cysts of the pancreas are mainly encountered in the mid-aged male population.