BACKGROUND Effusion cytology is a major diagnostic tool in medicine and has both therapeutic and prognostic implications. One of the dilemmas encountered is the differentiation between atypical cells and reactive mesothelial cells. The use of ancillary tools can reduce this grey zone and help to achieve a definitive diagnosis. OBJECTIVES The main objective of this study was to evaluate the role of flow cytometry (FCM) and cell block with immunohistochemistry (IHC), along with the clinicoradiological investigations, to achieve a final diagnosis in effusion cytology to the maximum extent possible. METHOD A prospective study was conducted. Effusion fluids, showing adequate amount and cellularity, were processed for conventional cytology, ploidy analysis by FCM, and cell block analysis, followed by IHC wherever required. Conventional cytological analysis was done by 2 independent pathologists, to look for interobserver variation, if any. The final result was achieved on the basis of integration of the results of the aforementioned studies, cytological details, clinicoradiological information, tissue biopsy findings, and follow-up. RESULT A total of 90 samples were analyzed. On cytological examination, observer I categorized 60% samples as benign and 18.8% (n = 17) as malignant versus 58% categorized as benign and 23.3% (n = 21) as malignant by observer II. Observer I reported 19 (21.1%) equivocal cases and observer II reported 16 (17.7%). When both pathologists were considered together, the number of equivocal cases increased to 20. Sensitivity and specificity of FCM were 96.67 and 100%, respectively, and 100% for the cell block. On combining all techniques, the equivocal cases were resolved and a total of 33 cases were reported as malignant. However, 3 cases could still not be categorized and were labeled inconclusive. CONCLUSION Conventional cytology combined with cell block IHC and FCM has the potential to minimize the requirement of tissue biopsy for confirmation. If the first sample is used judiciously for all the techniques, this may reduce the requirement for a second sample and possibly also the time required for a definite diagnosis and the initiation of therapy.

中文翻译：

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DNA倍性分析和细胞块免疫组织化学在恶性积液诊断中的应用。

背景技术积液细胞学是医学中的主要诊断工具，具有治疗和预后意义。遇到的难题之一是非典型细胞与反应性间皮细胞之间的分化。使用辅助工具可以减少该灰色区域并有助于实现明确的诊断。目的本研究的主要目的是评估流式细胞仪（FCM）和免疫组织化学（IHC）的细胞阻滞作用，以及临床放射学研究，以最大程度地实现积液细胞学的最终诊断。方法进行了一项前瞻性研究。对显示出足够数量和细胞性的输液进行常规细胞学检查，FCM倍性分析和细胞块分析，然后在需要时进行IHC处理。常规的细胞学分析由2位独立的病理学家完成，以寻找观察者之间的差异（如果有）。根据上述研究结果，细胞学细节，临床放射学信息，组织活检结果和随访结果的综合，获得了最终结果。结果总共分析了90个样品。在细胞学检查中，观察者I将60％的样本归为良性，将18.8％（n = 17）归为恶性，而将58％的样本归为良性，将23.3％（n = 21）归为恶性。观察员I报告了19起（21.1％）模棱两可的案件，观察员II报告了16起（17.7％）。当两个病理学家一起考虑时，模棱两可的病例数增加到20。FCM的敏感性和特异性分别为96.67和100％，对细胞阻滞的敏感性为100％。结合所有技术，模棱两可的案件得到解决，总共报告了33例恶性肿瘤。但是，仍有3个案例无法归类，并没有定论。结论常规细胞学结合细胞块IHC和FCM具有将组织活检确认所需的可能性降至最低的潜力。如果明智地将第一个样本用于所有技术，则可以减少对第二个样本的需求，并可能减少明确诊断和开始治疗所需的时间。