title: [New WHO classification of lung adenocarcinoma and preneoplasia].
abstract: The 2015 WHO classification of tumors of the lung, pleura, thymus and heart has just been published with numerous important changes from the 2004 WHO classification. The most significant changes involve (1) use of immunohistochemistry throughout the classification, (2) integration of molecular testing for personalized strategies for advanced lung cancer patients, (3) a new classification for small biopsies and cytology, (4) a new classification of lung adenocarcinoma as proposed by the 2011 IASLC/ATS/ERS, (5) restriction of the diagnosis of large cell carcinoma only to resected tumors that lack any clear morphologic or immunohistochemical differentiation. Regarding adenocarcinoma, the terms bronchioloalveolar carcinoma (BAC) and mixed subtype adenocarcinoma have been suppressed and replaced for the former by the term adenocarcinoma in situ (AIS) as a preinvasive lesion to join atypical adenomatous hyperplasia (AAH). A new category has been defined, the minimally invasive adenocarcinoma (MIA), and invasive adenocarcinomas are now classified according to the predominant subtype after subtyping by semi-quantitatively percentage of various subtypes present in 5% increments. The term "lepidic" is restricted to a non-invasive component (previously classified as BAC) present as part of an invasive adenocarcinoma. "Invasive mucinous adenocarcinoma" is used for formerly adenocarcinomas classified as mucinous BAC, excluding tumors that meet criteria for AIS or MIA. The subtypes of clear cell and signet ring adenocarcinoma are discontinued, as well the term of mucinous cystadenocarcinoma, included in the category of colloid adenocarcinoma. Thus new classification of lung adenocarcinoma is sustained by genetics and has clinical impact for therapeutic strategies.
authors.affiliation: Département de biopathologie, MESOPATH, centre Léon-Bérard, 28, rue Laënnec, 69008 Lyon, France; Inserm U823, institut Albert-Bonniot, université Joseph-Fourier, 38043 Grenoble, France. Electronic address: sylvie.lantuejoul@lyon.unicancer.fr.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Lantuejoul
authors.affiliation: Service d'anatomie pathologique, institut universitaire du cancer de Toulouse oncopole, 1, avenue Irène-Joliot-Curie, 31059 Toulouse cedex 9, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Rouquette
authors.affiliation: Inserm U823, institut Albert-Bonniot, université Joseph-Fourier, 38043 Grenoble, France; Département d'anatomie et cytologie pathologiques, CHU Albert-Michallon, université Joseph-Fourier, 38043 Grenoble, France.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Brambilla
authors.affiliation: Department of pathology, memorial Sloan Kettering cancer center, New York, NY, États-Unis.
authors.forename: William D
authors.initials: WD
authors.lastname: Travis
mesh_terms: D000230:Adenocarcinoma / Q000145:classification* / Q000235:genetics / Q000473:pathology; D000077192:Adenocarcinoma of Lung; D014408:Biomarkers, Tumor / Q000235:genetics; D002278:Carcinoma in Situ / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000145:classification / Q000235:genetics / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008175:Lung Neoplasms / Q000145:classification* / Q000235:genetics / Q000473:pathology; D009361:Neoplasm Invasiveness; D011230:Precancerous Conditions / Q000473:pathology; D011379:Prognosis; D014944:World Health Organization
chemical_list: D014408:Biomarkers, Tumor
keywords: Adenocarcinoma in situ; Adénocarcinome avec invasion minime; Adénocarcinome in situ; Adénocarcinome invasif; Adénocarcinome mucineux invasif; Immunohistochemistry; Immunohistochimie; Invasive adenocarcinoma; Invasive mucinous adenocarcinoma; Minimally invasive adenocarcinoma; Molecular; Moléculaire; Predominant subtype; Sous-type prédominant