Objective: To explore the protocol for diagnosing thyroid nodules based on core needle biopsy (CNB) and study the biomarkers' application in distinguishing indeterminate samples.
Methods: Patients with thyroid nodules treated at Peking University First Hospital from 2015 to 2020 were reviewed. In the study, 598 cases with CNB and matched resected specimens were retrieved. According to "diagnostic categories of thyroid CNB" proposed by the Korean Endocrine Pathology Thyroid Core Needle Biopsy Study Group, the CNB samples were diagnosed as follows: Ⅰ, unsatisfactory; Ⅱ, benign; Ⅲ, indeterminate; Ⅳ, follicular neoplasm; Ⅴ, suspicious for malignancy; and Ⅵ, malignant. The samples of CNB Ⅲ were stained by immunohistochemistry (IHC) using antibodies against CK19, Galectin-3, HBME-1, and CD56, and detected by next-generation sequencing (NGS) using an OncoAim® thyroid cancer multigene assay kit (Singlera Genomics) that detected 26 genes. Taking the resected specimens' classification as the gold standard, the predictive value of CNB for determining the malignancy of thyroid nodules and the biomarkers for distinguishing the samples of CNB Ⅲ was calculated.
Results: The study included 598 patients, of which none were CNB Ⅰ, 40 cases were CNB Ⅱ, 40 cases were CNB Ⅲ, 32 cases were CNB Ⅳ, 35 cases were CNB Ⅴ, and 451 cases were CNB Ⅵ. The predictive value of CNB Ⅳ for determining follicular neoplasm was sensitivity (Sen) 100.00% and specificity (Sep) 100.00%, CNB Ⅴ-Ⅵ for determining malignancy was Sen 94.55% and Sep 100.00%, CNB Ⅱ for determining benign lesions was Sen 75.00% and Sep 99.80%. The predictive value of biomarkers for determining malignancy in cases of CNB Ⅲ was Sen 96.30% and Sep 92.31% by NGS, and Sen 81.48% and Sep 92.30% by IHC.
Conclusion: The Korean "diagnostic categories of thyroid CNB", which considers the histological specificity of CNB samples and the habits of clinicians, have strong operability, high diagnosis rate, and high clinical value. Under this framework, the cases of CNB Ⅵ should be treated with surgical operation, the cases of CNB Ⅴ-Ⅵ are recommended to be treated as malignant neoplasms, and the major cases of CNB Ⅱ could be followed up without worrisome except the one considered malignant by ultrasound. The value of biomarkers in distinguishing the cases of CNB Ⅲ is significant.
目的: 探讨甲状腺结节粗针穿刺活检(core needle biopsy, CNB)的病理诊断规范以及生物标记物在辅助良恶性肿瘤鉴别中的应用, 在此基础上分析甲状腺结节CNB的恶性确诊效率和临床价值。
方法: 从2015—2020年以甲状腺结节就诊于北京大学第一医院的病例中筛选出既有术前CNB又有匹配的手术标本的病例, 共598例。CNB样本的诊断, 遵循韩国内分泌病理学甲状腺粗针穿刺工作组推荐的甲状腺粗针穿刺活检病理分类标准: Ⅰ级, 不具有诊断价值; Ⅱ级, 良性; Ⅲ级, 不确定; Ⅳ级, 滤泡肿瘤; Ⅴ级, 可疑恶性; Ⅵ级, 恶性。本组中共有40例CNB Ⅲ级的病例, 进一步行免疫组织化学染色(immunohistochemistry, IHC)和二代测序(next-generation sequencing, NGS)。IHC采用抗体CK19、Galectin-3、HBME-1和CD56。NGS采用OncoAim®甲状腺癌多基因检测试剂盒, 共检测26个基因, 覆盖甲状腺癌常见的基因突变。以术后诊断为金标准, 分析CNB术前确诊恶性的效率, 以及生物标记物辅助CNB Ⅲ级病例良恶性鉴别的效率。
结果: 598例患者中, Ⅰ级0例, Ⅱ级40例, Ⅲ级40例, Ⅳ级32例, Ⅴ级35例, Ⅵ级451例。CNB Ⅳ级的病例术前确诊滤泡性肿瘤的灵敏度和特异度均为100.00%;CNB Ⅴ~Ⅵ级的病例术前确诊恶性的灵敏度为94.55%, 特异度为100.00%;CNB Ⅱ级的病例术前确诊良性的灵敏度为75.00%, 特异度为99.80%。生物标记物辅助CNB Ⅲ级病例确诊恶性的效率为: 将检测到"致病性"和"可疑致病性"突变定义为NGS阳性, 可获得96.30%的灵敏度和92.31%的特异度; 将CD56阴性或CD56阳性的同时其他三个标记物均阳性定义为IHC阳性, 可获得81.48%的灵敏度和92.30%的特异度。
结论: 韩国甲状腺粗针穿刺活检病理分类标准兼顾了CNB样本的组织学特殊性和临床医生的习惯, 具有可操作性强、术前确诊率高、临床参考价值大的优点, 值得推广。遵循该分类标准, Ⅳ级的病例均应进一步手术切除, 鉴别良恶性; Ⅴ~Ⅵ级的病例推荐遵循恶性肿瘤的处理原则; Ⅱ级的病例绝大部分可安心随访, 极个别B超检查高度怀疑恶性者可考虑再次活检; Ⅲ级的病例应用生物标记物可高效辅助良恶性的鉴别诊断。
Keywords: Core needle biopsy; Pathological diagnosis; Thyroid nodule.