Willner Jonathan, Zhou Fang, Moreira Andre L
Department of Pathology, NYU Langone Health, New York, NY 10016, USA.
Cancers (Basel). 2022 Apr 15;14(8):2013. doi: 10.3390/cancers14082013.
Thymic epithelial neoplasms are rare tumors that constitute the majority of anterior mediastinal masses. They are classified as thymomas, thymic carcinomas, and thymic neuroendocrine neoplasms. Biopsy diagnosis is not common, and most tumors are surgically resected. Biopsy, including cytology, is indicated when a non-surgical entity is suspected or in cases of locally advanced disease. Smears of thymomas consist of round or spindle epithelial cells admixed with varying amounts of lymphocytes depending on the type of thymoma. Smears of thymic carcinoma and thymic neuroendocrine neoplasms are often indistinguishable from corresponding tumor types from other organs. Accurate cytological diagnosis can be difficult due to the histological diversity of thymomas, as well as the morphological features that certain thymic tumors share with similar tumors from other organs. However, fine needle aspiration (FNA) of anterior mediastinal masses can provide clinically actionable information and can be used to determine whether lesions require surgical, systemic, or local noninvasive treatments. Ancillary studies, namely, immunocytochemical stains, flow cytometry, and radiology, are important tools in the evaluation of thymic aspirates. This review discusses the utility and limitations of thymic FNAs and illustrates the diagnostic features and pitfalls of these specimens.
胸腺上皮性肿瘤是罕见肿瘤，占前纵隔肿块的大多数。它们分为胸腺瘤、胸腺癌和胸腺神经内分泌肿瘤。活检诊断并不常见，大多数肿瘤通过手术切除。当怀疑为非手术性病变或局部晚期疾病时，需进行活检，包括细胞学检查。胸腺瘤涂片由圆形或梭形上皮细胞组成，并根据胸腺瘤的类型混有不同数量的淋巴细胞。胸腺癌和胸腺神经内分泌肿瘤的涂片通常与其他器官相应肿瘤类型难以区分。由于胸腺瘤的组织学多样性以及某些胸腺肿瘤与其他器官类似肿瘤共有的形态学特征，准确的细胞学诊断可能具有挑战性。然而，前纵隔肿块的细针穿刺抽吸（FNA）可提供临床可行的信息，并可用于确定病变是否需要手术、全身或局部非侵入性治疗。辅助研究，即免疫细胞化学染色、流式细胞术和放射学，是评估胸腺穿刺物的重要工具。本文综述讨论了胸腺FNA的实用性和局限性，并阐述了这些标本的诊断特征和陷阱。
