Department of Pathology, MetroHealth Medical Center, Case Western Reserve University, Cleveland, Ohio, USA.
Department of Psychiatry, Case Western Reserve University, Cleveland, Ohio, USA.
Diagn Cytopathol. 2020 Dec;48(12):1199-1204. doi: 10.1002/dc.24541. Epub 2020 Jul 9.
Body fluids are rich in histiocytes and may mimic atypical epithelial cells morphologically. Histiocytes can pose a significant challenge in serous fluid cytology as they tend to appear atypical due to prolonged accumulation in serous fluids in vivo and processing by liquid-based cytology in vitro. Not many studies have documented the utilization of histiocytic marker such as CD68 in serous fluid cytology, which can subsequently reduce the "atypical" diagnostic category.
One thousand one hundred and twenty-nine cases of serous fluid cytology from 2016 to 2019 were reviewed and reclassified based on proposed classification of the international system for reporting serous fluid cytology. There were 133 cases with atypical diagnoses, out of which 51 cases had cellblocks. An immunohistochemistry (IHC) panel, including two mesothelial markers, two epithelial markers, and one histiocytic marker was applied to the atypical samples. Same IHC panel was utilized to evaluate 15 cases each from negative for malignancy (NFM), suspicious for malignancy (SFM), and malignant (MAL) categories for further comparison.
After reevaluation of the cytology material with IHC stains, 924 (82%), 133 (12%), 23 (2%), and 49 (4%) of the cases were reclassified as NFM, atypia of uncertain significance, SFM, and MAL, respectively. Twenty-five out of 51 atypical cases (49%) were downgraded to "benign" after reevaluation with CD68 IHC.
Histiocytes can mimic atypical epithelial cells in body fluids. Effective utilization of CD68 IHC will be beneficial in further refining the "atypical" diagnostic category in serous fluid cytology.
体液中富含组织细胞，其形态学表现可能类似于非典型上皮细胞。由于组织细胞在体内的浆膜液中长时间蓄积，并在体外的液体基础细胞学处理过程中发生改变，因此在浆膜液细胞学检查中，它们往往表现出非典型性，这给诊断带来了很大的挑战。目前，在浆膜液细胞学检查中，利用组织细胞标志物（如 CD68）的研究并不多，而这可能会减少“非典型”的诊断类别。
对 2016 年至 2019 年的 1129 例浆膜液细胞学检查病例进行了回顾性分析，并根据国际浆膜液细胞学报告系统提出的分类方法进行了重新分类。其中，有 133 例为不典型诊断病例，其中 51 例有细胞块。对这些不典型样本应用了免疫组织化学（IHC）检测，包括两种间皮标志物、两种上皮标志物和一种组织细胞标志物。同样的 IHC 检测也用于评估阴性恶性肿瘤（NFM）、可疑恶性肿瘤（SFM）和恶性肿瘤（MAL）组的各 15 例病例，以进行进一步比较。
在使用 IHC 染色重新评估细胞学材料后，924 例（82%）、133 例（12%）、23 例（2%）和 49 例（4%）病例分别被重新分类为 NFM、意义不明的非典型性、SFM 和 MAL。在对 51 例不典型病例中的 25 例（49%）进行 CD68 IHC 重新评估后，其诊断降级为“良性”。
组织细胞在体液中可能模拟非典型上皮细胞。有效的 CD68 IHC 利用将有助于进一步细化浆膜液细胞学检查中的“非典型”诊断类别。
