The algorithm of morphological diagnostics of pancreatic cystic formation including true cystic tumors, solid neoplasm with secondary cystic formation, nonneoplastic true cysts and pseudocysts are submitted. The determination of epithelial lining type specific for different neoplasms is a crucial factor. Tumors with border-line metastatic potential and carcinomas has been diagnosing in the detection of dysplasia and cell atopy features. On a number of occasions it's necessary to carry out an immunohistochemical investigation facilitating the differential diagnostics of neoplasms and determined the type of epithelium in intraductal papillary-mucinous tumors.