Andrew Churg1, Kazuki Nabeshima2, Greta Ali3, Rossella Bruno4, Lynnette Fernandez-Cuesta5, Francoise Galateau-Salle6. 1. Department of Pathology, Vancouver General Hospital and University of British Columbia, Vancouver, BC, Canada. Electronic address: achurg@mail.ubc.ca. 2. Department of Pathology, Fukuoka University School of Medicine and Hospital, Fukuoka, Japan. 3. Unit of Pathological Anatomy, University Hospital of Pisa, Italy. 4. Department of Surgical, Medical, Molecular Pathology and Critical Area, University of Pisa, Italy. 5. Genetic Cancer Susceptibility Group, Section of Genetics, International Agency for Research on Cancer, Lyon, France. 6. Centre National Référent MESOPATHm Centre Leon Berard, Lyon, France.
Abstract
OBJECTIVES: The separation of benign from malignant mesothelial proliferations and exact subclassification of mesothelioma subtypes is crucial to determining patient care and prognosis but morphologically can be very difficult. METHODS: This session of the 2018 IMIG meeting addressed these problems. RESULTS: A new immunohistochemical marker, methylthioadenosine phosphorylase, was shown to correlate well with CDKN2A FISH and is cheaper and faster to run. A 117 gene expression panel also provided good separation on both tissue biopsy and cytology samples. Review of a series of mesotheliomas thought to be biphasic produced only a moderate level of agreement among expert pathologists with some cases being classified as purely epithelioid or sarcomatoid; these classifications had prognostic significance. The entity called transitional mesothelioma was found to behave exactly like sarcomatoid mesothelioma. RNA-seq analysis of a large series of mesotheliomas from a public database showed that, genetically, the morphologic breakdown into epithelioid, sarcomatoid, or biphasic mesotheliomas is artificial because there is a continuous spectrum of genomic changes. There are now criteria for the diagnosis of mesothelioma in situ and this is potentially important, since such cases might be curable. CONCLUSIONS: This session documented new morphological and molecular approaches to separating benign from malignant mesothelial proliferations and to subclassifying malignant mesoteheliomas in clinical relevant ways.
OBJECTIVES: The separation of benign from malignant mesothelial proliferations and exact subclassification of mesothelioma subtypes is crucial to determining patient care and prognosis but morphologically can be very difficult. METHODS: This session of the 2018 IMIG meeting addressed these problems. RESULTS: A new immunohistochemical marker, methylthioadenosine phosphorylase, was shown to correlate well with CDKN2A FISH and is cheaper and faster to run. A 117 gene expression panel also provided good separation on both tissue biopsy and cytology samples. Review of a series of mesotheliomas thought to be biphasic produced only a moderate level of agreement among expert pathologists with some cases being classified as purely epithelioid or sarcomatoid; these classifications had prognostic significance. The entity called transitional mesothelioma was found to behave exactly like sarcomatoid mesothelioma. RNA-seq analysis of a large series of mesotheliomas from a public database showed that, genetically, the morphologic breakdown into epithelioid, sarcomatoid, or biphasic mesotheliomas is artificial because there is a continuous spectrum of genomic changes. There are now criteria for the diagnosis of mesothelioma in situ and this is potentially important, since such cases might be curable. CONCLUSIONS: This session documented new morphological and molecular approaches to separating benign from malignant mesothelial proliferations and to subclassifying malignant mesoteheliomas in clinical relevant ways.
Authors: Francoise Galateau Salle; Nolwenn Le Stang; Franck Tirode; Pierre Courtiol; Andrew G Nicholson; Ming-Sound Tsao; Henry D Tazelaar; Andrew Churg; Sanja Dacic; Victor Roggli; Daniel Pissaloux; Charles Maussion; Matahi Moarii; Mary Beth Beasley; Hugues Begueret; David B Chapel; Marie Christine Copin; Allen R Gibbs; Sonja Klebe; Sylvie Lantuejoul; Kazuki Nabeshima; Jean-Michel Vignaud; Richard Attanoos; Luka Brcic; Frederique Capron; Lucian R Chirieac; Francesca Damiola; Ruth Sequeiros; Aurélie Cazes; Diane Damotte; Armelle Foulet; Sophie Giusiano-Courcambeck; Kenzo Hiroshima; Veronique Hofman; Aliya N Husain; Keith Kerr; Alberto Marchevsky; Severine Paindavoine; Jean Michel Picquenot; Isabelle Rouquette; Christine Sagan; Jennifer Sauter; Francoise Thivolet; Marie Brevet; Philippe Rouvier; William D Travis; Gaetane Planchard; Birgit Weynand; Thomas Clozel; Gilles Wainrib; Lynnette Fernandez-Cuesta; Jean-Claude Pairon; Valerie Rusch; Nicolas Girard Journal: J Thorac Oncol Date: 2020-03-09 Impact factor: 15.609