Abstract：
BACKGROUND: Medullary thyroid carcinoma (MTC) is a rare cancer of parafollicular C-cell origin. The International MTC Grading System (IMTCGS) incorporates mitotic activity, the presence of necrosis, and the Ki67 proliferation rate (PR) to classify MTCs as low or high grade. The ability to predict IMTCGS grade in cytology was assessed.
METHODS: MTCs with cytology and subsequent surgical follow-up were reviewed. Cytology slides were reviewed for mitotic figures, apoptoses, and necrosis, and a Ki67 PR was calculated when possible. Findings were correlated with final IMTCGS grade.
RESULTS: Twenty-five MTC fine-needle aspirations (FNAs) were identified, with nine identified as high grade (36%). By using a PR cutoff of 5%, Ki67 on FNA material (Ki67FNA) showed 92% concordance (n = 22 of 24) with surgical Ki67 and a correlation coefficient (R2) of 0.72. Sensitivity and specificity of Ki67FNA for predicting high-grade MTC were 38% and 100%, respectively. Multiple mitotic figures were present in a single slide of 43% (n = 3 of 7) of evaluable high-grade MTCs, whereas only one of 16 low-grade MTCs showed a single mitotic figure. Definitive apoptoses were present in five of seven high-grade MTC FNAs but were absent in 16 low-grade MTCs. The sensitivity and specificity of apoptoses/necrosis on cytology for high-grade MTCs were 71% and 88%, respectively.
CONCLUSIONS: Ki67FNA ≥5% shows low sensitivity but high specificity for predicting high-grade MTC. The presence of multiple mitotic figures in a single slide or definitive apoptotic bodies are both highly suggestive of high-grade MTC, and should warrant a close examination for necrosis and a careful Ki67 PR count.
METHODS: MTCs with cytology and subsequent surgical follow-up were reviewed. Cytology slides were reviewed for mitotic figures, apoptoses, and necrosis, and a Ki67 PR was calculated when possible. Findings were correlated with final IMTCGS grade.
RESULTS: Twenty-five MTC fine-needle aspirations (FNAs) were identified, with nine identified as high grade (36%). By using a PR cutoff of 5%, Ki67 on FNA material (Ki67FNA) showed 92% concordance (n = 22 of 24) with surgical Ki67 and a correlation coefficient (R2) of 0.72. Sensitivity and specificity of Ki67FNA for predicting high-grade MTC were 38% and 100%, respectively. Multiple mitotic figures were present in a single slide of 43% (n = 3 of 7) of evaluable high-grade MTCs, whereas only one of 16 low-grade MTCs showed a single mitotic figure. Definitive apoptoses were present in five of seven high-grade MTC FNAs but were absent in 16 low-grade MTCs. The sensitivity and specificity of apoptoses/necrosis on cytology for high-grade MTCs were 71% and 88%, respectively.
CONCLUSIONS: Ki67FNA ≥5% shows low sensitivity but high specificity for predicting high-grade MTC. The presence of multiple mitotic figures in a single slide or definitive apoptotic bodies are both highly suggestive of high-grade MTC, and should warrant a close examination for necrosis and a careful Ki67 PR count.
摘要：
背景：甲状腺髓样癌（MTC）是一种罕见的滤泡旁C细胞起源的癌症。国际MTC分级系统（IMTCGS）结合有丝分裂活动，坏死的存在，和Ki67增殖率（PR）将MTCs分为低级别或高级别。评估了在细胞学中预测IMTCGS分级的能力。
方法：对MTCs的细胞学检查和随后的手术随访进行综述。检查细胞学切片的有丝分裂图，凋亡，和坏死，并在可能的情况下计算Ki67PR。结果与最终IMTCGS等级相关。
结果：确定了25个MTC细针穿刺（FNA），其中9人被确定为高等级(36%)。通过使用5%的PR截止值，FNA材料上的Ki67（Ki67FNA）与手术Ki67显示出92％的一致性（24个中的n=22），相关系数（R2）为0.72。Ki67FNA预测高级别MTC的敏感性和特异性分别为38%和100%,分别。43％（7个中的n=3）的可评估高级MTC的单个幻灯片中存在多个有丝分裂图，而16个低级别的MTC中只有一个显示出单一的有丝分裂图。明确的凋亡存在于七个高级MTCFNA中的五个中，但在16个低级MTC中却不存在。细胞凋亡/坏死对高级别MTC的敏感性和特异性分别为71％和88％，分别。
结论：Ki67FNA≥5%对预测高级别MTC的敏感性低，但特异性高。单个载玻片或确定的凋亡小体中存在多个有丝分裂图，都高度暗示了高级MTC，并且应该需要仔细检查坏死和仔细的Ki67PR计数。
方法：对MTCs的细胞学检查和随后的手术随访进行综述。检查细胞学切片的有丝分裂图，凋亡，和坏死，并在可能的情况下计算Ki67PR。结果与最终IMTCGS等级相关。
结果：确定了25个MTC细针穿刺（FNA），其中9人被确定为高等级(36%)。通过使用5%的PR截止值，FNA材料上的Ki67（Ki67FNA）与手术Ki67显示出92％的一致性（24个中的n=22），相关系数（R2）为0.72。Ki67FNA预测高级别MTC的敏感性和特异性分别为38%和100%,分别。43％（7个中的n=3）的可评估高级MTC的单个幻灯片中存在多个有丝分裂图，而16个低级别的MTC中只有一个显示出单一的有丝分裂图。明确的凋亡存在于七个高级MTCFNA中的五个中，但在16个低级MTC中却不存在。细胞凋亡/坏死对高级别MTC的敏感性和特异性分别为71％和88％，分别。
结论：Ki67FNA≥5%对预测高级别MTC的敏感性低，但特异性高。单个载玻片或确定的凋亡小体中存在多个有丝分裂图，都高度暗示了高级MTC，并且应该需要仔细检查坏死和仔细的Ki67PR计数。
