*Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany; †Institute of Pathology, University of Göttingen, Göttingen, Germany; ‡Department of Pathology, Indiana University Health Pathology Laboratory, Indianapolis, Indiana; §Department of Pathology, Louis Pradel Hospital, Hospices Civils de Lyon, Lyon, France; ‖Department of Pathology, Queen Elizabeth Hospital, Hong Kong, China; ¶Department of Pathology, Shanghai Pulmonary Hospital and Tongji University School of Medicine, Shanghai, China; #University Institute of Pathology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; **Department of Thoracic Surgery, Yale University School of Medicine, New Haven, Connecticut; ††Department of Respiratory Medicine, Louis Pradel Hospital, Hospices Civils de Lyon, Lyon, France; ‡‡Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York; §§Division of Pathology, Zurich, Switzerland; ‖‖Department of Pathology, Catholic University, Rome, Italy; ¶¶Department of Pathology, Regina Elena National Cancer Institute, Rome, Italy; ##Department of Diagnostic Pathology, Hokkaido University Hospital, Sapporo, Japan; ***Department of Pathology, AP-HP, Necker, University Paris Descartes, Paris, France; †††Department of Diagnostic Pathology, Saiseikai Central Hospital, Tokyo, Japan; ‡‡‡Diagnostic Thoracic Pathology, Royal Brompton Hospital, and Imperial College London, London, United Kingdom; §§§Department of Histopathology, The Cristie Hospital, and Institute of Cancer Sciences, The University of Manchester, Manchester, United Kingdom; ‖‖‖Institute of Pathology, University of Erlangen, Erlangen, Germany; ¶¶¶Centro Diagnostico Italiano, Milano, Italy; ###Department of Thoracic Surgery, University of Torino, Torino, Italy; and ****Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, New York.
J Thorac Oncol. 2014 May;9(5):596-611. doi: 10.1097/JTO.0000000000000154.
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.
2004 年版世界卫生组织分类将胸腺瘤分为 A、AB、B1、B2 和 B3（以及罕见的其他）胸腺瘤和胸腺癌（TC）。由于一些胸腺瘤亚型之间存在形态学连续性，以及胸腺瘤和 TC 之间存在一些形态学重叠，因此一些病例在分类上可能存在问题，导致某些研究中的观察者间可重复性较差。
为了克服这个问题，在国际胸腺癌兴趣小组的支持下，由 18 位病理学家参加了一个国际共识幻灯片研讨会，对典型的“交界性”和“混合性”胸腺瘤和 TC 的苏木精-伊红染色和免疫组织化学处理切片进行了研究（n=72）。
在 A/AB 交界区、B1、B2 和 B3 胸腺瘤之间的区别以及 B3 胸腺瘤与 TC 的分离方面，达成了精细决策标准的共识。暂时提出“非典型A型胸腺瘤”作为一种新的 A 型胸腺瘤变体。提出了具有多种组织学模式的肿瘤的新报告策略。
这些指南可以为胸腺上皮肿瘤的可重复性研究和临床有意义的分级系统的设计奠定基础。
