细针穿刺细胞学在甲状腺癌中漏诊误诊原因及临床价值分析

Analysis of the causes of missed diagnosis and misdiagnosis of FNAC in thyroid cancer and its clinical application value

目的 分析细针穿刺细胞学(FNAC)在所有甲状腺癌诊断中的应用情况及漏诊、误诊原因,进一步探讨其在甲状腺癌中的临床应用价值。方法 收集2021年1月—2022年1月在西南医科大学附属医院行甲状腺FNAC的397例病例,应用穿刺涂片HE染色、细胞蜡块、免疫细胞化学、术中冰冻及术后常规组织病理切片、免疫组织化学、基因检测,根据甲状腺癌[包括甲状腺乳头状癌(PTC)、甲状腺滤泡癌(FTC)、甲状腺髓样癌(MTC)及未分化型甲状腺癌(ATC)]各自的细胞学特异性特征,将所有标本分为低危组和高危组,并对所有漏诊及误诊的病例进行原因分析。结果 所有的病例中,高危组243例,低危组154例,其中滤泡性肿瘤符合率为94.12%(32/34);PTC符合率为97.47%(193/198);不能确定类型的甲状腺癌及可疑MTC符合率为100%(11/11),总的误诊率为2.47%(6/243)。误诊原因可能为:腺瘤性甲状腺肿、桥本氏甲状腺炎等良性病变中,部分细胞核发生毛玻璃样改变且呈伴有乳头状增生时,容易过诊断为PTC;滤泡性肿瘤中除了大量微滤泡,典型的梁状结构更具诊断特征性,当细胞具有明显的异型性时,容易过诊断为可疑FTC。低危组随访7例为甲状腺微小乳头状癌(其中2例经基因检测诊断),其余均为良性病变,漏诊率为4.55%(7/154)。漏诊原因可能为:肿瘤直径小于0.5 cm,距离体表距离超过2 cm,穿刺细胞量过少,出血明显等。结论 FNAC不仅能较为准确的诊断PTC,且在其余的甲状腺癌诊断中也有相当高的应用价值,可作为所有甲状腺癌术前诊断的首选检查方法。同时,细胞病理医生也应及时总结各类型甲状腺癌的细胞病理学特征,结合彩超定位、免疫细胞化学及基因检测等技术,尽量为临床提供精确诊断。

Objective To analyze the application of fine needle aspiration cytology(FNAC)in the diagnosis of thyroid cancer and the causes of missed diagnosis and misdiagnosis,and further explore its clinical application value in thyroid cancer.Methods A total of 397 cases of thyroid FNAC in the Affiliated Hospital of Southwest Medical University from January 2021 to January 2022 were collected.Fine needle aspiration smears were stained with Hematoxylin-eosin(HE),cell-block,immunocytochemistry,intra-operative frozen section and Postoperative histopathological sections,immunohistochemistry and genetic testing were performed.According to the specific cytological characteristics of thyroid cancer(PTC,FTC,MTC and ATC),all samples were divided into low-and high-risk groups,and the causes of missed diagnosis and misdiagnosis were analyzed.Results There were 243 cases in high-risk group and 154 cases in low-risk group.The concordance rate of the diagnosis was 94.12%in follicular neoplasm,97.47%in PTC,100%in indeterminate type of thyroid cancer and suspicious MTC,and the total misdiagnosis rate was 2.47%.The causes of misdiagnosis may be as follows:In benign lesions such as adenomatous goiter and Hashimoto′s thyroiditis,some nuclear ground-glass changes with papillary hyperplasia are easy to be overdiagnosed as PTC.In addition to a large number of microfollicles,the typical trabecular structure is more specific for diagnosis in follicular tumors,it is easy to be overdiagnosed as suspicious FTC when the tumor cells showed prominent atypia.In the low-risk group,7 cases were diagnosed as Papillary thyroid microcarcinoma(including 2 cases diagnosed by genetic testing),and the rest were benign lesions,with a missed diagnosis rate of 4.55%.The causes of missed diagnosis may be:the diameter of the tumor was less than 0.5cm,the distance from the skin surface was more than 2cm,the amount of tumor cells was small,and the significant was bleeded from needle puncture.Conclusion FNAC is not only accurate in the diagnosis of PTC,but also has considerable high value in the diagnosis of other thyroid cancers.It should be used as the first choice in the preoperative diagnosis of all thyroid cancers.At the same time,cytopathologists should also summarize the cytopathological characteristics of various types of thyroid cancer in time,combined with color Doppler ultrasound,immunocytochemistry and genetic testing,as far as possible to provide accurate diagnosis for clinical practice.