Alexandra Meurgey1, Nicolas Girard2, Claire Merveilleux du Vignaux3, Jean-Michel Maury4, François Tronc4, Françoise Thivolet-Bejui5, Lara Chalabreysse5. 1. Department of Pathology, Louis-Pradel Hospital, Hospices Civils de Lyon, Lyon, France. 2. Department of Respiratory Medicine, National Expert Centre for Thymic Malignancies, Cancer Institute of the Hospices Civils de Lyon, Louis-Pradel Hospital, Lyon, France; Lyon University, Claude Bernard Lyon-1 University, Lyon, France. Electronic address: nicolas.girard@chu-lyon.fr. 3. Department of Respiratory Medicine, National Expert Centre for Thymic Malignancies, Cancer Institute of the Hospices Civils de Lyon, Louis-Pradel Hospital, Lyon, France. 4. Lyon University, Claude Bernard Lyon-1 University, Lyon, France; Department of Thoracic Surgery, Louis Pradel Hospital, Hospices Civils de Lyon, Lyon, France. 5. Department of Pathology, Louis-Pradel Hospital, Hospices Civils de Lyon, Lyon, France; Lyon University, Claude Bernard Lyon-1 University, Lyon, France.
Abstract
INTRODUCTION: Thymic epithelial tumors (TETs) are rare intrathoracic malignancies that are categorized histologically according to the WHO classification, which was recently updated in 2015 on the basis of a consensus statement of the International Thymic Malignancy Interest Group (ITMIG); at the same time, the standard Masaoka-Koga staging system is scheduled to be replaced by the eighth edition of the TNM staging classification by the American Joint Committee on Cancer/Union for International Cancer Control consortium. Our objectives were to analyze the feasibility of assessing ITMIG consensus major and minor morphological and immunohistochemical criteria and the eighth edition of the TNM staging classification in a routine practice setting. METHODS: This is a single-center study conducted at the Louis-Pradel Hospital of Lyon University, one of the largest centers for TETs in France. Overall, a large surgical series of 188 TETs diagnosed in 181 patients between 2000 and 2014 at our center were analyzed. RESULTS: There were 89 men (49%) and 92 women (51%); 57 patients (31%) presented with myasthenia gravis at time of diagnosis. According to the WHO classification, there were nine type A thymomas (5%), 67 type AB thymomas (36%), 19 type B1 thymomas (10%), 46 type B2 thymomas (24%), 27 type B3 thymomas (14%), and 20 thymic carcinomas (11%). ITMIG consensus major criteria were identified in 100% of type A, AB, B1, and B2 thymomas. After restaging according to the eighth edition of the TNM staging classification, there were 127 stage I (84%), three stage II (2%), 17 stage IIIa (11%), no stage IIIb, two stage IVa (1%), and three stage IVb (2%) thymomas. Significant correlation between histological type and stage at diagnosis was maintained after restaging according the TNM classification. CONCLUSION: Comprehensive analysis of our well-characterized surgical series of 188 TETs indicates the feasibility and the diagnostic value of the ITMIG consensus statement on WHO histological classification and highlights the major switch in staging when the eighth edition of the TNM staging classification is applied.
INTRODUCTION: Thymic epithelial tumors (TETs) are rare intrathoracic malignancies that are categorized histologically according to the WHO classification, which was recently updated in 2015 on the basis of a consensus statement of the International Thymic Malignancy Interest Group (ITMIG); at the same time, the standard Masaoka-Koga staging system is scheduled to be replaced by the eighth edition of the TNM staging classification by the American Joint Committee on Cancer/Union for International Cancer Control consortium. Our objectives were to analyze the feasibility of assessing ITMIG consensus major and minor morphological and immunohistochemical criteria and the eighth edition of the TNM staging classification in a routine practice setting. METHODS: This is a single-center study conducted at the Louis-Pradel Hospital of Lyon University, one of the largest centers for TETs in France. Overall, a large surgical series of 188 TETs diagnosed in 181 patients between 2000 and 2014 at our center were analyzed. RESULTS: There were 89 men (49%) and 92 women (51%); 57 patients (31%) presented with myasthenia gravis at time of diagnosis. According to the WHO classification, there were nine type A thymomas (5%), 67 type AB thymomas (36%), 19 type B1 thymomas (10%), 46 type B2 thymomas (24%), 27 type B3 thymomas (14%), and 20 thymic carcinomas (11%). ITMIG consensus major criteria were identified in 100% of type A, AB, B1, and B2 thymomas. After restaging according to the eighth edition of the TNM staging classification, there were 127 stage I (84%), three stage II (2%), 17 stage IIIa (11%), no stage IIIb, two stage IVa (1%), and three stage IVb (2%) thymomas. Significant correlation between histological type and stage at diagnosis was maintained after restaging according the TNM classification. CONCLUSION: Comprehensive analysis of our well-characterized surgical series of 188 TETs indicates the feasibility and the diagnostic value of the ITMIG consensus statement on WHO histological classification and highlights the major switch in staging when the eighth edition of the TNM staging classification is applied.
Authors: Gabrielle Drevet; Stéphane Collaud; François Tronc; Nicolas Girard; Jean-Michel Maury Journal: Cancer Manag Res Date: 2019-07-22 Impact factor: 3.989