Abstract：
Mucoepidermoid carcinoma (MEC) and sclerosing MEC with eosinophilia (SMECE) are rare primary thyroid carcinomas. In this study, we aimed to present our multicenter series of MEC and SMECE and integrated our data with published literature to further investigate the clinicopathological characteristics and prognoses of these tumors. We found 2 MECs and 4 SMECEs in our multicenter archives. We performed fluorescence in situ hybridization (FISH) to determine the MAML2 gene rearrangement. We screened for mutations in BRAF, TERT promoter, and RAS mutations using Sanger sequencing and digital polymerase chain reaction. Histopathologically, MECs and SMECEs were composed of two main cell types including epidermoid and mucin-secreting cells, arranged in cords, nests, and tubules. SMECEs were characterized by a densely sclerotic stroma with abundant eosinophils. We did not detect any MAML2 fusion in any of our cases. Two MEC cases harbored concomitant BRAF p.V600E and TERT C228T mutations. RAS mutations were absent in all cases. Concurrent foci of another thyroid malignancy were more commonly seen in MECs (p < 0.001), whereas SMECEs were associated with chronic lymphocytic thyroiditis (p < 0.001). MECs and SMECEs had equivalent recurrence-free survival (RFS) but MECs conferred significantly dismal disease-specific survival (DSS) as compared to SMECEs (p = 0.007). In conclusion, MECs and SMECEs not only shared some similarities but also demonstrated differences in clinicopathological characteristics, prognoses, and molecular profiles. SMECEs had a superior DSS in comparison to MECs, suggesting that they are low-grade cancers. This could help clinicians better evaluate patient outcomes and decide appropriate treatment plans.
摘要：
粘液表皮样癌（MEC）和伴有嗜酸性粒细胞增多的硬化性MEC（SMECE）是罕见的原发性甲状腺癌。在这项研究中,我们旨在介绍我们的多中心MEC和SMECE系列,并将我们的数据与已发表的文献进行整合,以进一步研究这些肿瘤的临床病理特征和预后.我们在多中心档案中发现了2个MEC和4个SMECE。我们进行了荧光原位杂交（FISH）以确定MAML2基因重排。我们筛选了BRAF的突变,TERT启动子,和RAS突变使用Sanger测序和数字聚合酶链反应。组织病理学,MECs和SMECEs由两种主要的细胞类型组成，包括表皮样细胞和粘蛋白分泌细胞。排列在绳索中，巢,和小管。SMECE的特征是浓密的硬化基质和丰富的嗜酸性粒细胞。在我们的任何病例中，我们都没有检测到任何MAML2融合。两个MEC病例伴随BRAFp.V600E和TERTC228T突变。所有病例均不存在RAS突变。另一种甲状腺恶性肿瘤的并发病灶更常见于MEC（p<0.001），而SMECEs与慢性淋巴细胞性甲状腺炎相关(p<0.001)。MEC和SMECE具有相等的无复发生存率（RFS），但与SMECE相比，MEC赋予了显着的疾病特异性生存率（DSS）（p=0.007）。总之,MEC和SMECE不仅有一些相似之处，而且在临床病理特征上也表现出差异。预后,和分子概况。与MEC相比，SMECE的DSS更优越，表明它们是低级别的癌症。这可以帮助临床医生更好地评估患者的预后并决定适当的治疗计划。
