The Significance of Hürthle Cells in Thyroid Disease

Learning Objectives After completing this course, the reader will be able to: Enumerate the variable thyroid pathological conditions in which Hürthle cells are seen and explain the significance of the findings within the appropriate clinical context. Describe the various means by which Hürthle cell neoplasms may be evaluated and their value in determining the likelihood of a benign or malignant lesion. This article is available for continuing medical education credit at CME.TheOncologist.com Hürthle cells (HCs) and HC change, along with the frequently employed synonyms “oncocytes/oncocytic change” or “oxyphils/oxyphilic change,” are not infrequently described on fine‐needle aspiration biopsy (FNAB) reports of thyroid lesions. The description of HCs on FNAB reports may cause significant concern to the clinician; however, placing the finding in the appropriate clinical context may alleviate some anxiety. Not all oxyphilic cells are true HCs and not every aspirate containing HCs is or should be considered equivalent to an HC neoplasm (HCN). There are many benign thyroid lesions associated with HCs or HC change. For clinicians, it may be difficult to discern the significance of these findings and to determine an appropriate course of action. A skilled and experienced cytopathologist is invaluable in discriminating the subtle features that distinguish these lesions from those warranting a more aggressive approach. The diagnosis of HC carcinoma relies on histopathologic scrutiny and evidence of capsular and/or vascular invasion or metastasis to lymph nodes or distant organs. Many investigators have sought clinical, radiographic, cytological, genetic, and other factors to attempt to discriminate preoperatively between benign and malignant HCNs. To date, none have been definitively proven to be reliable. For now, because of the inability to determine the benign or malignant nature of such neoplasms based on cytology alone, a surgical approach is warranted. 摘要 Hürthle细胞（HC）与HC改变（也常称为“大嗜酸性粒细胞/嗜酸性细胞改变”或“嗜酸性/嗜酸性改变”）在甲状腺病灶细针抽吸活检（FNAB）报告中并不罕见。FNAB报告对HC的描述可引起医生的极大关注；而合理解读其临床意义则可缓解部分焦虑。然而，并非所有嗜酸性细胞都是真正的HC，并非每例含有HC的针吸组织都被视为HC肿瘤（HCN）。有一些良性甲状腺病变亦可出现HC或HC改变。医生可能难以鉴别这些结果的意义，无法确定适当的疗程。技术娴熟、经验丰富的细胞病理学家在明确良恶性病灶的细微差异中所起作用就异常关键。HC癌的确诊依赖于组织病理学检查及包膜和（或）血管侵犯或淋巴结转移及远处转移的证据。很多研究者探讨了与HCN相关的临床、放射学、细胞学、遗传学及其他相关因素，以期于术前明确HCN的良恶性。然而迄今为止，尚无有效预测指标。由于目前仅基于细胞学检查尚不能区分肿瘤的良恶性，手术切除仍是有效手段。 Features that define Hürthle cells are clarified, various thyroid conditions associated with Hürthle cells are d