TY - JOUR
T1 - ITMIG Consensus Statement on the Use of the WHO Histological Classification of Thymoma and Thymic Carcinoma: Refined Definitions, Histological Criteria, and Reporting
AU - Marx, Alexander
AU - Ströbel, Philipp
AU - Badve, Sunil S.
AU - Chalabreysse, Lara
AU - Chan, John K.C.
AU - Chen, Gang
AU - De Leval, Laurence
AU - Detterbeck, Frank
AU - Girard, Nicolas
AU - Huang, Jim
AU - Kurrer, Michael O.
AU - Lauriola, Libero
AU - Marino, Mirella
AU - Matsuno, Yoshihiro
AU - Molina, Thierry Jo
AU - Mukai, Kiyoshi
AU - Nicholson, Andrew G.
AU - Nonaka, Daisuke
AU - Rieker, Ralf
AU - Rosai, Juan
AU - Ruffini, Enrico
AU - Travis, William D.
PY - 2014
Y1 - 2014
N2 - INTRODUCTION: 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.METHODS: 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.RESULTS: 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.CONCLUSION: These guidelines can set the stage for reproducibility studies and the design of a clinically meaningful grading system for thymic epithelial tumors.
AB - INTRODUCTION: 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.METHODS: 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.RESULTS: 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.CONCLUSION: These guidelines can set the stage for reproducibility studies and the design of a clinically meaningful grading system for thymic epithelial tumors.
KW - thymoma, thymic carcinoma, histological classification, diagnostic criteria
KW - thymoma, thymic carcinoma, histological classification, diagnostic criteria
UR - http://hdl.handle.net/10807/55872
U2 - 10.1097/JTO.0000000000000154
DO - 10.1097/JTO.0000000000000154
M3 - Article
SN - 1556-0864
SP - 596
EP - 611
JO - Journal of Thoracic Oncology
JF - Journal of Thoracic Oncology
ER -