title: Microadenocarcinoma of the pancreas.
abstract: BACKGROUND
  Microadenocarcinoma (MA) of the pancreas is a rare kind of neoplasm, whose status as an independent tumor entity is still a matter of controversy.
  
  
  RESULTS
  In this article we investigated two patients with MA from the histological, immunohistochemical and genetic aspects. Morphologically, MA is composed of small, crowded microglandular structures, forming a cribriform pattern, sometimes solid sheets. Cells of MA were morphologically uniform and were less pleomorphic than those of the ductal adenocarcinoma. Immunohistochemistry revealed that MA, though with a certain extent of epithelial differentiation, possesses a different immunological phenotype from those of ductal carcinoma, acinar cell carcinoma, and endocrine tumors. Genetic analysis showed no abnormality of p53, K-ras, and beta-catenin, which were usually mutated in pancreatic ductal adenocarcinoma.
  
  
  CONCLUSIONS
  Therefore, we suggest that MA should be taken as an independent tumor entity rather than a kind of growth pattern, but a final decision should be reached after cautious differential diagnosis of other kinds of pancreatic neoplasms.
authors.affiliation: Department of Pathology, Changhai Hospital, Shanghai, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Guanzhen
authors.initials: G
authors.lastname: Yu
authors.forename: Dalie
authors.initials: D
authors.lastname: Ma
authors.forename: Canrong
authors.initials: C
authors.lastname: Ni
authors.forename: Minghua
authors.initials: M
authors.lastname: Zhu
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D016133:Polymerase Chain Reaction / Q000379:methods; D018807:Polymorphism, Single-Stranded Conformational