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Copyright ©The Author(s) 2021.
World J Gastrointest Surg. May 27, 2021; 13(5): 406-418
Published online May 27, 2021. doi: 10.4240/wjgs.v13.i5.406
Table 1 Distinctive histologic features of pancreatic ductal adenocarcinoma and its benign mimics
PDACCPAIPPDP
Perineural invasion; perivascular invasion; naked glands in adipose tissue; desmoplasia; anisonucleosis (4:1 nuclear size variation)Intact lobular architecture; fibrosis; secretory plugsType I: Dense lymphoplasmacytic infiltrate with an increased IgG4 expression; storiform fibrosis; obliterative phlebitis. Type II: Granulocytes in the ductal epithelium; absent IgG4 positive cells.Duodenal wall thickening; brunner gland hyperplasia; smooth muscle hyperplasia; heterotopic pancreatic tissue
Table 2 Summary of morphologic features and altered genes of pancreatic ductal adenocarcinoma subtypes
SubtypeColloidMedullaryAdenosquamousHepatoidSignet ring cell
Morphologic featuresMore than 80% of extracellular mucin; focal signet-ring cells can be seenMinimal glandular differentiation; syncytial growth pattern; abundant inflammatory infiltrateMore than 30% of squamous differentiationMore than 50% of hepatocellular differentiationMore than 80% of signet ring cell component
Altered genesGNAS; ATMMMR genes; POLESMAD4; CDKN2ABAP1; Notch1NA