看穿刺没经验，还没有病史，只看这3张图，就大胆猜吧，错了不用负责：不除外低度恶性肿瘤，如髓样癌等。自己遇到可不敢报啊。

亚急性甲状腺炎

 等待学习

 Ok! Basically, the pictures show spindle cells in the thyroid aspirates. I agree that medullary carcinoma is in the differential. When I see spindle cells in thyroid FNA, the first thing you want to ask yourself is : is the spindle cell prolifeartion represent a non-neoplastic or neoplastic process? You can see  focal areas of spindle cells proliferation in nodular goiter, granulomatous thyroiditis, post therapy change, or granulation tissue. I have certainly made mistakes and I have seen other pathologists made mistakes on calling some focal reactive spindle cells neoplastic.

 On the other hand, if the whole case and every slides show this population of spindle cells, then there is great concern for a neoplastic process, for that, I usually make a cell block to do immunostains.

 译陈隆文博士帖子：

这例甲状腺穿刺，图片基本显示了梭形细胞。我同意髓样癌是鉴别诊断之一。在甲状腺细针穿刺中，看到梭形细胞，首先我会问自己梭形细胞是肿瘤细胞还是非肿瘤性的？在结节性甲状腺肿、肉芽肿性甲状腺炎、治疗后改变或肉芽组织，都能看到局灶梭形细胞增生。我自己、我也看到过别的病理医生犯过把局灶反应性的梭形细胞当作肿瘤性的这样的错误。同时，如果整个病例每张片子都显示大量梭形细胞，就要考虑是不是肿瘤性的，我通常做细胞块染免疫组化。