过去十年，肿瘤的分子标记和遗传学取得了指数级的进步，人们认识到传统组织病理学在分级、分类和预测方面的局限性。这些进步导致分类系统发生变化，例如，将客观分子和遗传信息纳入 2021 年世界卫生组织 (WHO) 中枢神经系统肿瘤分类。第五版WHO头颈肿瘤分类（HN5）（测试版在线版，2022年）也引入了基于分子标志物的重大变化，包括实体的增加、删除和重新分类，以更加客观和标准化。这些变化与治疗决策、预后和临床研究以及耐药性疾病患者在临床试验中探索选择高度相关。 HN5 首次邀请放射科医生作为编写团队的成员，将相关影像学结果纳入分类。对于放射科医生来说，作为多学科团队的一个组成部分，重要的是要及时了解这些变化，以便更好地了解肿瘤生物学，将其融入到他们的临床实践中，并在他们的解释中提供更多价值。作者为放射科医生提供了对病理学和遗传学的基本了解，强调了头颈部上皮细胞（包括鳞状细胞）和非上皮肿瘤的分子变化。作者还强调了新认识和重新分类的肿瘤实体，并对遗传性肿瘤综合征进行了简要讨论。 ©RSNA，2024 本文提供了补充材料。请参阅本期 Junn 和 Baugnon 特邀评论。

The past decade has seen exponential advancements in molecular markers and the genetics of tumors, recognizing the limitations of conventional histopathology for grading, classification, and prognostication. Such advances have resulted in changes to classification systems, for example, with the incorporation of objective molecular and genetic information into the 2021 World Health Organization (WHO) classification of central nervous system tumors. The fifth edition of the WHO classification of head and neck tumors (HN5) (beta online version, 2022) also introduced major changes based on molecular markers, including additions, deletions, and reclassifications of entities, with the idea of being more objective and standardized. These changes are highly relevant to therapy decisions, prognosis, and clinical research and for patients with resistant diseases to explore options in clinical trials. The HN5, for the first time, included a radiologist as a member of the writing team to incorporate pertinent imaging findings into the classification. It is important for the radiologist, as an integral part of the multidisciplinary team, to be up to date about these changes for a better understanding of tumor biology, to integrate this into their clinical practice, and to provide more value in their interpretations. The authors provide a basic understanding of pathology and genetics for the radiologist, highlighting the molecular changes in epithelial (including squamous cell) and nonepithelial tumors of the head and neck. The authors also highlight newly recognized and reclassified tumor entities and provide a brief discussion on the genetic tumor syndromes. ©RSNA, 2024 Supplemental material is available for this article. See the invited commentary by Junn and Baugnon in this issue.