Intraductal papillary mucinous neoplasm (IPMN) belong to benign epithelial tumors and precursors and are characterized by intracurrent papillary growths with abundant mucin secretion, leading to cystic expansion of the main or lateral pancreatic ducts. In some cases, the diagnosis of intraductal papillary mucinous neoplasm may be difficult in the absence of concomitant symptoms. Two clinical cases have been described. In the first case, patient N., 74 years old, was under dynamic observation for 5 years due to a single cyst in the pancreas (about 2 cm). During the next control study, single parietal soft tissue nodules accumulating a contrast agent were detected in the cyst cavity, which made it possible to suspect malignancy. Morphological examination of the resected pancreas revealed the diagnosis: IPMN of the pancreas associated with invasive ductal adenocarcinoma.

In the second case, patient A., 47 years old, had an acute onset of the disease after a deviation in diet. The preoperative diagnosis suggested the presence of either chronic (possibly paraduodenal) pancreatitis or a cystic tumor of the pancreatic head, but without obvious signs of malignancy of the process. After gastropancreatoduodenal resection and morphological examination of the removed macropreparation, IPMN of the pancreas was found in the head of the pancreas in association with a highly differentiated G1 ductal adenocarcinoma growing within the pancreatic parenchyma.

Thus, preoperative diagnosis of changes observed in the pancreas according to imaging research methods can be significantly difficult in the absence of alarming symptoms, which should be taken into account when formulating a preliminary diagnosis in difficult cases.