甲状腺结节内钙化的超声特征对结节良恶性的诊断价值

目的：评估甲状腺结节内钙化的大小、位置、数量、有无声影等超声特征对结节良恶性的诊断价值。方法：回顾性分析2015年7月至2017年4月浙江大学医学院附属第二医院超声怀疑恶性结节行细针穿刺细胞学（FNA）检查或者手术治疗的278个甲状腺钙化结节的超声图及临床病理资料。以手术结果或FNA的细胞学结合超声随访结果作为金标准，根据结节内钙化的大小分为≤1 mm、1～2 mm、＞2 mm 3组，分析各组的良恶性，从而确定粗大钙化的定义；分析粗大钙化的特征（数量、位置、有无声影）对结节的良恶性是否具有诊断价值。结果：超声怀疑恶性的甲状腺钙化结节，钙化≤1 mm与1～2 mm、＞2 mm之间的良恶性比例差异具有统计学意义（P＜0.05）；而1～2 mm与＞2 mm这2组间差异没有统计学意义（P＞0.05）；以钙化≤1 mm、≤2 mm作为标准预测甲状腺癌的敏感性（95%CI）为84.2%（78.1%～88.8%）、92.3%（87.4%～95.5%）；特异性（95%CI）分别为46.3%（35.4%～57.6%）、13.4%（7.2%～23.2%）；对于钙化＞1 mm的甲状腺结节，中央型钙化、周围型钙化、混合型钙化3组间的恶性率差异有统计学意义（P=0.003）；其中中央型钙化提示恶性，周围型钙化提示良性，而混合型钙化对良恶性的鉴别没有诊断价值；结节中钙化的数量、有无声影等特征对于良恶性的鉴别没有统计学意义（P＞0.05）。结论：钙化≤1 mm或中央型钙化可以作为预测甲状腺结节恶性的指标。

The value of ultrasonic characteristics of the thyroid nodule calcification in the diagnosis of thyroid cancer

Objective: To evaluate the diagnostic value of the calcification characteristics in the thyroid nodule including its size, location, quantity, and acoustic shadow. Methods: We reviewed sonographic findings of all calcified nodules which underwent ultrasound-guided fine needle aspiration (FNA) or surgery between July 2015 and April 2017. Surgical pathology or FNA cytology combined with follow-up result was regarded as the ‘Reference Test’. All nodules were firstly divided into three groups according to the size of calcification: ≤1 mm, 1~2 mm, >2 mm, and then the definition of macro-calcification (>1 mm or 2 mm) was determined by analysing the malignancy rate of each group. Secondly, sonographic characteristics of the macro-calcification including its location, quantity and acoustic shadow were analyzed. Results: Among suspiciously malignant nodules on ultrasound, the malignancy rate of nodule with calcification ≤1 mm was significantly higher than nodule with calcification 1~2 mm or >2 mm (P<0.05), and there was no significant difference between Group 1~2 mm and Group >2 mm (P>0.05). Among macro-calcified (>1 mm) thyroid nodules, calcification located in the center of the nodule was associated with malignancy while peripheral calcification was associated with benign nodule (P=0.003). However the ultrasonic features, including the quantity and acoustic shadow of the calcification had no significant effect on the diagnosis of thyroid cancer (P>0.05). Conclusion: Calcification ≤1 mm or macro-calcification located in the center of the nodule could be significant indications of thyroid cancer.