Frank Renee, Baloch Zubair W, Gentile Caren, Watt Christopher D, LiVolsi Virginia A
Division of Anatomic Pathology, Department of Pathology and Laboratory Medicine, University of Pennsylvania, 3400 Spruce Street, 6th Floor Founders Building, Philadelphia, PA, 19104, USA.
Endocr Pathol. 2014 Sep;25(3):236-40. doi: 10.1007/s12022-013-9289-0.
Multifocal fibrosing thyroiditis (MFT) is characterized by numerous foci of fibrosis in a stellate configuration with fibroelastotic and fibroblastic centers entrapping epithelial structures. MFT has been proposed as a risk factor for papillary thyroid carcinoma (PTC) development. We attempted to identify whether MFT showed such molecular changes and could possibly be related to PTC. We identified seven cases of PTC with MFT in our institutional pathology database and personal consult service of one of the authors (VAL) for the years 1999 to 2012. Areas of PTC, MFT, and normal tissue were selected for BRAF analysis. Macro-dissection, DNA extraction and PCR amplification, and pyrosequencing were performed to detect BRAF mutations in codon 600. All of the MFT lesions and normal thyroid tissue were negative for BRAF mutations. Of the seven PTCs analyzed, five (71 %) were negative for BRAF mutations, while two cases were positive. In our study, none of the MFT lesions harbored BRAF mutations, whereas 29 % (two of seven) PTCs in the same gland were positive. Hence, in this small study, we found no evidence that the MFT lesion is a direct precursor to PTC. It is likely an incidental bystander in the process and a reflection of the background thyroiditis.
多灶性纤维性甲状腺炎（MFT）的特征是存在众多呈星状排列的纤维化病灶，其纤维弹性中心和成纤维细胞中心包绕上皮结构。MFT已被认为是甲状腺乳头状癌（PTC）发生的一个危险因素。我们试图确定MFT是否呈现出此类分子变化，以及是否可能与PTC相关。我们在机构病理数据库以及其中一位作者（VAL）1999年至2012年的个人会诊服务中，识别出7例伴有MFT的PTC病例。选取PTC、MFT及正常组织区域进行BRAF分析。进行宏观解剖、DNA提取及PCR扩增，并采用焦磷酸测序检测第600密码子处的BRAF突变。所有MFT病灶及正常甲状腺组织的BRAF突变均为阴性。在分析的7例PTC中，5例（71%）BRAF突变阴性，2例阳性。在我们的研究中，没有一个MFT病灶存在BRAF突变，而同一腺体内29%（7例中的2例）的PTC为阳性。因此，在这项小型研究中，我们没有发现证据表明MFT病灶是PTC的直接前驱病变。它很可能是该过程中的一个偶然旁观者，反映了背景性甲状腺炎。
