title: Utilization of ancillary studies in the cytologic diagnosis of biliary and pancreatic lesions: The Papanicolaou Society of Cytopathology Guidelines.
abstract: The Papanicolaou Society of Cytopathology has developed a set of guidelines for pancreatobiliary cytology including indications for endoscopic ultrasound guided fine needle aspiration, terminology and nomenclature of pancreatobiliary disease, ancillary testing and post-biopsy management. All documents are based on the expertise of the authors, a review of the literature, discussion of the draft document at several national and international meetings and synthesis of selected online comments of the draft document. This document presents the results of these discussions regarding the use of ancillary testing in the cytologic diagnosis of biliary and pancreatic lesions. Currently, fluorescence in-situ hybridization (FISH) appears to be the most clinically relevant ancillary technique for cytology of bile duct strictures. The addition of FISH analysis to routine cytologic evaluation appears to yield the highest sensitivity without loss in specificity. Loss of immunohistochemical staining for the protein product of the SMAD4 gene and positive staining for mesothelin support a diagnosis of ductal adenocarcinoma. Immunohistochemical markers for endocrine and exocrine differentiation are sufficient for a diagnosis of endocrine and acinar tumors. Nuclear staining for beta-catenin supports a diagnosis of solid-pseudopapillary neoplasm. Cyst fluid analysis for amylase and carcinoembryonic antigen aids in the pre-operative classification of pancreatic cysts. A number of gene mutations (KRAS, GNAS, von Hippel-Lindau, RNF43 and CTNNB1) may be of aid in the diagnosis of cystic neoplasms. Other ancillary techniques do not appear to improve diagnostic sensitivity sufficiently to justify their increased costs.
authors.affiliation: Address: Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, Missouri, USA.
authors.forename: Lester J
authors.initials: LJ
authors.lastname: Layfield
authors.affiliation: Department of Pathology, Fox Chase Cancer Center, Philadelphia, PA, USA.
authors.forename: Hormoz
authors.initials: H
authors.lastname: Ehya
authors.affiliation: Laboratory of Pathology, National Cancer Institute, Bethesda, USA.
authors.forename: Armando C
authors.initials: AC
authors.lastname: Filie
authors.affiliation: The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Ralph H
authors.initials: RH
authors.lastname: Hruban
authors.affiliation: Department of Pathology and Laboratory Medicine, The Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Nirag
authors.initials: N
authors.lastname: Jhala
authors.affiliation: Department of Pathology, The University of Chicago, Chicago, Illinois, USA.
authors.forename: Loren
authors.initials: L
authors.lastname: Joseph
authors.affiliation: Department of Pathology, Institut Gustave Roussy, Villejuif, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Vielh
authors.affiliation: Department of Pathology, The Massachusetts General Hospital, Harvard University, Boston, Massachusetts, USA.
authors.forename: Martha B
authors.initials: MB
authors.lastname: Pitman
keywords: Ancillary studies; biliary tract; endoscopic ultrasound; fine-needle aspiration; molecular diagnosis; pancreas