title: Different amounts of K-ras mutant epithelial cells in pancreatic carcinoma and mass-forming pancreatitis.
abstract: Clinically, differential diagnosis of pancreatic carcinoma (PC) and so-called "mass-forming pancreatitis (MFP)" is difficult. We analyzed the amount, ductal level, and K-ras mutation of ductal hyperplasia and intraductal carcinoma in surgically resected cases of MFP (n = 18) and PC (n = 16). DNAs extracted from microdissected epithelial foci were analyzed for K-ras codon 12 mutation by nested polymerase chain reaction and restriction fragment length polymorphism. The histology of MFP showed severe destruction of exocrine tissue and pancreatic stones and/or protein plugs (72%, 13 of 18 cases) in mostly peripheral ducts. The average basal membrane lengths of nonpapillary and papillary hyperplasia in cases of carcinoma were about 4 and 15 times more than those of MFP, respectively. The frequency of K-ras mutation in hyperplastic foci increased from nonpapillary [six (27%) of 22] to papillary foci [16 (64%) of 25] in K-ras mutant PCs, but there was no difference between nonpapillary [one (6%) of 18] and papillary foci (none of 19) in K-ras wild-type PCs, and also between nonpapillary (none of 24) and papillary foci [one (7%) of 14] in MFPs.
authors.affiliation: First Department of Pathology, Niigata University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Matsubayashi
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Ajioka
authors.forename: K
authors.initials: K
authors.lastname: Nishikura
authors.forename: M
authors.initials: M
authors.lastname: Yamano
authors.forename: T
authors.initials: T
authors.lastname: Seki
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.forename: T
authors.initials: T
authors.lastname: Matsubayashi
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D002462:Cell Membrane / Q000473:pathology; D002908:Chronic Disease; D003062:Codon; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D011905:Genes, ras; D006801:Humans; D006965:Hyperplasia; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010183:Pancreatic Ducts / Q000378:metabolism / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D010195:Pancreatitis / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies
chemical_list: D003062:Codon