Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Cancer Cytopathol. 2020 Jan;128(1):57-67. doi: 10.1002/cncy.22211. Epub 2019 Nov 19.
Fine-needle aspiration (FNA), a minimally invasive and cost-effective procedure, often is used in the initial diagnosis of thymic lesions. However, the diagnosis can be challenging. Knowledge of the diagnostic pitfalls is important to improve diagnostic accuracy.
The authors retrospectively searched the pathology database of The University of Texas MD Anderson Cancer Center for FNA cases using the keywords "thymoma" or "thymic" in cytologic diagnoses or in corresponding final histologic diagnoses rendered from January 2002 to June 2018. The authors reviewed the FNA diagnostic accuracy and pitfalls in comparison with the final histologic diagnoses.
A total of 118 FNA cases were identified from 115 patients. The FNA diagnoses were concordant with the final pathologic diagnoses in 110 cases (93.2%), including thymoma (97 cases), atypical thymoma (5 cases), and thymic carcinoma (8 cases). Discrepant FNA and final diagnoses were noted in 8 tumors (6.8%): thymoma versus atypical thymoma/thymic carcinoma (3 tumors), thymoma versus lymphoma (2 tumors), suspicious for lymphoma versus thymoma (1 tumor), and T-lymphoblastic lymphoma versus thymoma (2 tumors). Factors contributing to misinterpretation included intrinsic limitations of the FNA sample (sampling error and a lack of histologic architecture information) and similarities of the cytologic and immunophenotypic features of lymphocyte-rich thymoma and T-lymphoblastic lymphoma.
An accurate FNA diagnosis of thymic tumors can be rendered in the majority of cases. Diagnostic pitfalls can be encountered in rare cases. It is important to handle each case carefully to avoid erroneous diagnoses that may lead to inappropriate treatment.
细针穿刺（FNA）是一种微创且具有成本效益的程序，常用于胸腺瘤的初步诊断。然而，诊断具有一定挑战性。了解诊断陷阱对于提高诊断准确性非常重要。
作者回顾性地检索了 2002 年 1 月至 2018 年 6 月期间，使用细胞学诊断或相应的最终组织学诊断中含有“胸腺瘤”或“胸腺”的关键词，在德克萨斯大学 MD 安德森癌症中心的病理学数据库中搜索 FNA 病例。作者比较了 FNA 诊断的准确性和与最终组织学诊断的差异。
共从 115 名患者中确定了 118 例 FNA 病例。FNA 诊断与最终病理诊断一致的有 110 例（93.2%），包括胸腺瘤（97 例）、非典型胸腺瘤（5 例）和胸腺癌（8 例）。8 例肿瘤的 FNA 诊断与最终诊断不一致（6.8%）：胸腺瘤与非典型胸腺瘤/胸腺癌（3 例）、胸腺瘤与淋巴瘤（2 例）、疑似淋巴瘤与胸腺瘤（1 例）、T 淋巴细胞性淋巴瘤与胸腺瘤（2 例）。导致误诊的因素包括 FNA 样本的固有局限性（采样误差和缺乏组织学结构信息），以及富含淋巴细胞的胸腺瘤和 T 淋巴细胞性淋巴瘤的细胞学和免疫表型特征相似。
大多数情况下可以对胸腺瘤进行准确的 FNA 诊断。在罕见情况下可能会遇到诊断陷阱。处理每个病例时要小心谨慎，以避免可能导致不适当治疗的错误诊断非常重要。
