Benign vs malignant pancreatic lesions: Molecular insights to an ongoing debate

Table 1 Distinctive histologic features of pancreatic ductal adenocarcinoma and its benign mimics

PDAC	CP	AIP	PDP
Perineural invasion; perivascular invasion; naked glands in adipose tissue; desmoplasia; anisonucleosis (4:1 nuclear size variation)	Intact lobular architecture; fibrosis; secretory plugs	Type 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

PDAC: Pancreatic ductal adenocarcinoma; CP: Chronic pancreatitis; AIP: Autoimmune pancreatitis; PDP: Paraduodenal pancreatitis.