ITMIG consensus statement on the use of the WHO histological classification of thymoma and thymic carcinoma: refined definitions, histological criteria, and reporting

Marx A, Stroebel P, Badve SS, Chalabreysse L, Chan JKC, Chen G, De Leval L, Detterbeck F, Girard N, Huang J, Kurrer MO, Lauriola L, Marino M, Matsuno Y, Molina TJ, Mukai K, Nicholson AG, Nonaka D, Rieker R, Rosai J, Ruffini E, Travis WD (2014)

Publication Type: Journal article

Publication year: 2014

Journal

Book Volume: 9

Pages Range: 596-611

Journal Issue: 5

DOI: 10.1097/JTO.0000000000000154

Abstract

The 2004 version of the World Health Organization classification subdivides thymic epithelial tumors into A, AB, B1, B2, and B3 (and rare other) thymomas and thymic carcinomas (TC). Due to a morphological continuum between some thymoma subtypes and some morphological overlap between thymomas and TC, a variable proportion of cases may pose problems in classification, contributing to the poor interobserver reproducibility in some studies.To overcome this problem, hematoxylin-eosin-stained and immunohistochemically processed sections of prototypic, "borderland," and "combined" thymomas and TC (n = 72) were studied by 18 pathologists at an international consensus slide workshop supported by the International Thymic Malignancy Interest Group.Consensus was achieved on refined criteria for decision making at the A/AB borderland, the distinction between B1, B2, and B3 thymomas and the separation of B3 thymomas from TCs. "Atypical type A thymoma" is tentatively proposed as a new type A thymoma variant. New reporting strategies for tumors with more than one histological pattern are proposed.These guidelines can set the stage for reproducibility studies and the design of a clinically meaningful grading system for thymic epithelial tumors.

Involved external institutions

Memorial Sloan Kettering Cancer Center United States (USA) (US) University of Turin / Università degli Studi di Torino (UNITO) Italy (IT) CDI Centro Diagnostico Italiano S.p.A. Italy (IT) Christie NHS Foundation Trust United Kingdom (GB) Royal Brompton Hospital United Kingdom (GB) Saiseikai Central Hospital Japan (JP) University of Paris 5 - René Descartes / Université Paris V René Descartes France (FR) Hokkaido University (Hokudai) / 北海道大学 Japan (JP) Fondazione IRCCS: Istituto Nazionale dei Tumori Italy (IT) Catholic University of the Sacred Heart / Università Cattolica del Sacro Cuore Italy (IT) Hospices Civils de Lyon (CHU) France (FR) Yale University United States (USA) (US) Lausanne University Hospital / Centre hospitalier universitaire vaudois (CHUV) Switzerland (CH) Shanghai Pulmonary Hospital China (CN) Queen Elizabeth Hospital / 伊利沙伯醫院 China (CN) Indiana University United States (USA) (US) Ruprecht-Karls-Universität Heidelberg Germany (DE)

How to cite

APA:

Marx, A., Stroebel, P., Badve, S.S., Chalabreysse, L., Chan, J.K.C., Chen, G.,... Travis, W.D. (2014). ITMIG consensus statement on the use of the WHO histological classification of thymoma and thymic carcinoma: refined definitions, histological criteria, and reporting. Journal of Thoracic Oncology, 9(5), 596-611. https://dx.doi.org/10.1097/JTO.0000000000000154

MLA:

Marx, Alexander, et al. "ITMIG consensus statement on the use of the WHO histological classification of thymoma and thymic carcinoma: refined definitions, histological criteria, and reporting." Journal of Thoracic Oncology 9.5 (2014): 596-611.

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