Abstract：
BACKGROUND: Sclerosing Mucoepidermoid Carcinoma with Eosinophilia (SMECE) of the thyroid is an extremely rare tumor that exhibits unique histologic characteristics and is nearly always associated with lymphocytic thyroiditis (LT). However, the cytomorphologic and clinicopathologic characteristics of SMECE have only been described in rare case reports.
METHODS: Authors\' institution laboratory information systems were searched for records of SMECE between 2012 and 2023. Literature review was performed using keywords \"Sclerosing mucoepidermoid carcinoma with eosinophilia\", \"thyroid\", and \"cytopathology\" to search through institution electronic library databases for relevant articles.
RESULTS: A total of 19 cases were identified, 3 unpublished in the authors\' archives and 16 in the literature which had fine needle aspiration (FNA) material or cytologic features available for review, and were comprised of 3 males and 16 females. The common cytomorphologic characteristics of SMECE included fragments or loose clusters of intermediate-type epidermoid cells in a background of prominent LT and eosinophils. Overt keratinization, mucinous cells, and extracellular mucin were not commonly encountered, resulting in diagnostic challenges, especially if eosinophils associated with epithelial cell clusters were rare. The cases were reported as \"Nondiagnostic\" (1 case), \"Atypia of Undetermined Significance\" (4 cases), \"Suspicious for Malignancy\" (3 case), or \"Malignant\" (11 cases).
CONCLUSIONS: The clinical course of SMECE of the thyroid varied and distinct cytomorphologic characteristics in a subset of patients who experienced aggressive disease raises the possibility of different prognostic grades. Cases with keratinized squamous cells and necrosis mimic anaplastic (undifferentiated) thyroid carcinoma, but the clinical history and radiologic findings can be helpful to exclude this diagnosis.
METHODS: Authors\' institution laboratory information systems were searched for records of SMECE between 2012 and 2023. Literature review was performed using keywords \"Sclerosing mucoepidermoid carcinoma with eosinophilia\", \"thyroid\", and \"cytopathology\" to search through institution electronic library databases for relevant articles.
RESULTS: A total of 19 cases were identified, 3 unpublished in the authors\' archives and 16 in the literature which had fine needle aspiration (FNA) material or cytologic features available for review, and were comprised of 3 males and 16 females. The common cytomorphologic characteristics of SMECE included fragments or loose clusters of intermediate-type epidermoid cells in a background of prominent LT and eosinophils. Overt keratinization, mucinous cells, and extracellular mucin were not commonly encountered, resulting in diagnostic challenges, especially if eosinophils associated with epithelial cell clusters were rare. The cases were reported as \"Nondiagnostic\" (1 case), \"Atypia of Undetermined Significance\" (4 cases), \"Suspicious for Malignancy\" (3 case), or \"Malignant\" (11 cases).
CONCLUSIONS: The clinical course of SMECE of the thyroid varied and distinct cytomorphologic characteristics in a subset of patients who experienced aggressive disease raises the possibility of different prognostic grades. Cases with keratinized squamous cells and necrosis mimic anaplastic (undifferentiated) thyroid carcinoma, but the clinical history and radiologic findings can be helpful to exclude this diagnosis.
摘要：
背景：甲状腺硬化性粘膜表皮样癌伴嗜酸性粒细胞增多（SMECE）是一种极其罕见的肿瘤，具有独特的组织学特征，几乎总是与淋巴细胞性甲状腺炎（LT）相关。然而,SMECE的细胞形态和临床病理特征仅在罕见病例报告中有所描述.
方法：作者机构实验室信息系统在2012年至2023年之间搜索了SMECE的记录。使用关键词“伴有嗜酸性粒细胞增多的硬化性黏液表皮样癌”进行文献综述“甲状腺”，和“细胞病理学”，通过机构电子图书馆数据库搜索相关文章。
结果：共确认19例，作者档案中有3个未发表，文献中有16个有细针穿刺（FNA）材料或细胞学特征可供审查，由3名男性和16名女性组成。SMECE的常见细胞形态学特征包括在突出的LT和嗜酸性粒细胞背景下的中间型表皮样细胞的碎片或松散簇。明显角质化,粘液细胞，和细胞外粘蛋白并不常见，导致诊断挑战，特别是如果与上皮细胞簇相关的嗜酸性粒细胞很少。病例报告为“非诊断性”(1例)，“不确定意义的异常”(4例)，“恶性肿瘤可疑”(3例)，或“恶性”(11例)。
结论：在经历侵袭性疾病的患者亚组中，甲状腺SMECE的临床过程不同且不同的细胞形态学特征增加了不同预后分级的可能性。角化鳞状细胞和坏死模拟间变性（未分化）甲状腺癌的病例，但病史和影像学检查有助于排除这种诊断.
方法：作者机构实验室信息系统在2012年至2023年之间搜索了SMECE的记录。使用关键词“伴有嗜酸性粒细胞增多的硬化性黏液表皮样癌”进行文献综述“甲状腺”，和“细胞病理学”，通过机构电子图书馆数据库搜索相关文章。
结果：共确认19例，作者档案中有3个未发表，文献中有16个有细针穿刺（FNA）材料或细胞学特征可供审查，由3名男性和16名女性组成。SMECE的常见细胞形态学特征包括在突出的LT和嗜酸性粒细胞背景下的中间型表皮样细胞的碎片或松散簇。明显角质化,粘液细胞，和细胞外粘蛋白并不常见，导致诊断挑战，特别是如果与上皮细胞簇相关的嗜酸性粒细胞很少。病例报告为“非诊断性”(1例)，“不确定意义的异常”(4例)，“恶性肿瘤可疑”(3例)，或“恶性”(11例)。
结论：在经历侵袭性疾病的患者亚组中，甲状腺SMECE的临床过程不同且不同的细胞形态学特征增加了不同预后分级的可能性。角化鳞状细胞和坏死模拟间变性（未分化）甲状腺癌的病例，但病史和影像学检查有助于排除这种诊断.
