Abstract：
BACKGROUND: Thyroid malignancy is one of the most common types of cancer in developed nations. Currently, fine-needle aspiration cytology (FNAC) is the most practical screening test for thyroid nodules. However, cytologically indeterminate samples comprise approximately 15%-30% of cases. These include cases classified as atypia of undetermined significance (AUS), follicular neoplasm (FN), and suspicious for malignancy (SFM). Indeterminate cases can be sent for molecular testing for more definitive classification to help guide management and prevent overtreatment of benign thyroid nodules. We conducted a retrospective review on molecular testing of indeterminate thyroid FNAC and reviewed subsequent histologic diagnoses in resection specimens to assess how molecular testing supported a diagnosis and its effect on clinical management of patients at our institution.
METHODS: A retrospective chart review was performed on all thyroid FNAC specimens, corresponding molecular testing, and subsequent surgical resection specimens over a 6-year period.
RESULTS: A total of 10,253 thyroid FNAC were performed in our hospital system during our study period, of which 10% (n = 1102/10,253) had indeterminate FNAC results. Molecular testing was performed in 16% (n = 178/1102) of indeterminate cytology cases. Genetic alterations were identified in 39% (n = 69/178) of the cases sent for molecular testing. The majority of cytologically indeterminate cases sent for molecular testing were follicular-patterned lesions and their corresponding resection specimens revealed mostly low grade follicular derived neoplasms (i.e., follicular adenoma, non-invasive follicular thyroid neoplasm with papillary-like nuclear features, and follicular variant of papillary thyroid carcinoma). Of the cases with identified genetic alterations, 75% (n = 52/69) were treated surgically. In cases with no genetic alterations identified, only 18% (n = 20/109) were treated surgically.
CONCLUSIONS: Molecular testing on cytologically indeterminate thyroid nodules can help provide a more accurate risk of malignancy assessment in patients with lesions that are difficult to diagnosis based solely on FNAC morphology. The types of genetic alterations identified in the resected thyroid lesions were consistent with what has been previously described in the literature. Additionally, we found that in the patients with indeterminate thyroid FNAC with adjunct molecular testing, more than half did not undergo surgical resection. This finding emphasizes the value of adding molecular testing in patients, particularly when attempting to reduce unnecessary surgical intervention.
METHODS: A retrospective chart review was performed on all thyroid FNAC specimens, corresponding molecular testing, and subsequent surgical resection specimens over a 6-year period.
RESULTS: A total of 10,253 thyroid FNAC were performed in our hospital system during our study period, of which 10% (n = 1102/10,253) had indeterminate FNAC results. Molecular testing was performed in 16% (n = 178/1102) of indeterminate cytology cases. Genetic alterations were identified in 39% (n = 69/178) of the cases sent for molecular testing. The majority of cytologically indeterminate cases sent for molecular testing were follicular-patterned lesions and their corresponding resection specimens revealed mostly low grade follicular derived neoplasms (i.e., follicular adenoma, non-invasive follicular thyroid neoplasm with papillary-like nuclear features, and follicular variant of papillary thyroid carcinoma). Of the cases with identified genetic alterations, 75% (n = 52/69) were treated surgically. In cases with no genetic alterations identified, only 18% (n = 20/109) were treated surgically.
CONCLUSIONS: Molecular testing on cytologically indeterminate thyroid nodules can help provide a more accurate risk of malignancy assessment in patients with lesions that are difficult to diagnosis based solely on FNAC morphology. The types of genetic alterations identified in the resected thyroid lesions were consistent with what has been previously described in the literature. Additionally, we found that in the patients with indeterminate thyroid FNAC with adjunct molecular testing, more than half did not undergo surgical resection. This finding emphasizes the value of adding molecular testing in patients, particularly when attempting to reduce unnecessary surgical intervention.
摘要：
背景：甲状腺恶性肿瘤是发达国家中最常见的癌症类型之一。目前,细针穿刺细胞学检查(FNAC)是甲状腺结节最实用的筛查方法.然而,细胞学上不确定的样本约占病例的15％-30％。这些包括分类为不确定意义的非典型（AUS）的病例，滤泡性肿瘤（FN），并怀疑为恶性肿瘤（SFM）。可以将不确定的病例进行分子检测，以进行更明确的分类，以帮助指导管理并防止良性甲状腺结节的过度治疗。我们对不确定的甲状腺FNAC的分子检测进行了回顾性审查，并在切除标本中回顾了随后的组织学诊断，以评估分子检测如何支持诊断及其对我们机构患者临床管理的影响。
方法：对所有甲状腺FNAC标本进行回顾性分析，相应的分子测试，以及随后的6年手术切除标本。
结果：在我们的研究期间，我们的医院系统共进行了10,253甲状腺FNAC，其中10%(n=1102/10,253)的FNAC结果不确定。在16％（n=178/1102）的不确定细胞学病例中进行了分子检测。在发送进行分子检测的病例中，有39％（n=69/178）发现了遗传改变。大多数送去进行分子检测的细胞学不确定病例是滤泡样病变，其相应的切除标本大多显示低度滤泡源性肿瘤（即，滤泡性腺瘤,具有乳头状样细胞核特征的非侵袭性滤泡性甲状腺肿瘤，和甲状腺乳头状癌的滤泡变体）。在确定的遗传改变的病例中，75％（n=52/69）接受手术治疗。在没有发现遗传改变的情况下，只有18%(n=20/109)接受手术治疗.
结论：对细胞学上不确定的甲状腺结节进行分子检测可以帮助对单纯基于FNAC形态难以诊断的病变患者提供更准确的恶性肿瘤风险评估。在切除的甲状腺病变中鉴定的遗传改变类型与文献中先前描述的一致。此外,我们发现，在甲状腺FNAC不确定的患者中，通过辅助分子检测，一半以上没有接受手术切除.这一发现强调了在患者中增加分子检测的价值，特别是当试图减少不必要的手术干预。
方法：对所有甲状腺FNAC标本进行回顾性分析，相应的分子测试，以及随后的6年手术切除标本。
结果：在我们的研究期间，我们的医院系统共进行了10,253甲状腺FNAC，其中10%(n=1102/10,253)的FNAC结果不确定。在16％（n=178/1102）的不确定细胞学病例中进行了分子检测。在发送进行分子检测的病例中，有39％（n=69/178）发现了遗传改变。大多数送去进行分子检测的细胞学不确定病例是滤泡样病变，其相应的切除标本大多显示低度滤泡源性肿瘤（即，滤泡性腺瘤,具有乳头状样细胞核特征的非侵袭性滤泡性甲状腺肿瘤，和甲状腺乳头状癌的滤泡变体）。在确定的遗传改变的病例中，75％（n=52/69）接受手术治疗。在没有发现遗传改变的情况下，只有18%(n=20/109)接受手术治疗.
结论：对细胞学上不确定的甲状腺结节进行分子检测可以帮助对单纯基于FNAC形态难以诊断的病变患者提供更准确的恶性肿瘤风险评估。在切除的甲状腺病变中鉴定的遗传改变类型与文献中先前描述的一致。此外,我们发现，在甲状腺FNAC不确定的患者中，通过辅助分子检测，一半以上没有接受手术切除.这一发现强调了在患者中增加分子检测的价值，特别是当试图减少不必要的手术干预。
