Renshaw Andrew A, Haja Jennifer C, Neal Margaret H, Wilbur David C
Department of Pathology, Baptist Hospital of Miami, Miami, Fla, USA.
Arch Pathol Lab Med. 2006 Nov;130(11):1612-5. doi: 10.5858/2006-130-1612-DCTOTM.
The cytologic features of carcinoid tumor in mediastinal fine-needle aspiration are well described. Nevertheless, this tumor may be difficult to distinguish from thymoma in this site.
We sought to correlate the cytologic features of carcinoid tumor of the mediastinum in the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytopathology with the frequency of misclassification as thymoma.
We reviewed 446 interpretations from 18 different cases of carcinoid tumor in mediastinum and correlated the cytologic features with performance.
Cases were more frequently classified as thymoma (158 responses, 35%) than as carcinoid tumor (126 responses, 28%). The best-performing case was classified as carcinoid tumor only 56% of the time. Three cytologic patterns were identified. Four cases consisted of isolated round cells with salt-and-pepper chromatin. Four cases consisted of isolated spindle and round cells with salt-and-pepper chromatin. The remaining 10 cases consisted of cohesive fragments of crowded cells with finely granular chromatin showing numerous pyknotic cells mimicking lymphocytes. Prominent vasculature patterns were not a feature of any of the cases. There was no correlation between any pattern and the rate of classification as carcinoid tumor or thymoma (P > .05).
Carcinoid tumor of the mediastinum is frequently misclassified as thymoma in this program. Although some cytologic patterns resemble thymoma, the lack of correlation of these patterns with performance suggests that at least part of the reason for misclassification may be failure to consider the correct diagnosis or a lack of familiarity with discriminating cytologic criteria.
纵隔细针穿刺中类癌肿瘤的细胞学特征已有充分描述。然而，该部位的这种肿瘤可能难以与胸腺瘤区分。
我们试图将美国病理学家学会非妇科细胞病理学实验室间比较项目中纵隔类癌肿瘤的细胞学特征与误诊为胸腺瘤的频率相关联。
我们回顾了18例纵隔类癌肿瘤不同病例的446份诊断结果，并将细胞学特征与诊断表现相关联。
病例被诊断为胸腺瘤（158份诊断结果，35%）的频率高于被诊断为类癌肿瘤（126份诊断结果，28%）。表现最佳的病例被诊断为类癌肿瘤的时间仅为56%。确定了三种细胞学模式。4例由具有“椒盐”样染色质的孤立圆形细胞组成。4例由具有“椒盐”样染色质的孤立梭形和圆形细胞组成。其余10例由紧密排列的细胞凝聚性碎片组成，染色质呈细颗粒状，可见大量模仿淋巴细胞的固缩细胞。显著的血管模式在任何病例中均未出现。任何一种模式与诊断为类癌肿瘤或胸腺瘤的比率之间均无相关性（P >.05）。
在该项目中，纵隔类癌肿瘤经常被误诊为胸腺瘤。尽管一些细胞学模式类似胸腺瘤，但这些模式与诊断表现缺乏相关性表明，误诊的至少部分原因可能是未考虑正确诊断或对鉴别细胞学标准不熟悉。
