A Retrospective Analysis of Serous Effusions Based on the Newly Proposed International System for Reporting Serous Fluid Cytopathology: A Report of 3633 Cases in an Oncological Center

Background: The International System for Reporting Serous Fluid Cytopathology (TIS) was recently proposed. We retrospectively applied TIS recommendations for reporting the cytological diagnosis of serous effusions and reported our experience.Methods: All the serous effusions from January 2018 to September 2021 were retrieved from the database. Recategorization was performed using the TIS classification, the risk of malignancy (ROM) was calculated for each TIS category, and the performance evaluation was carried out among different samples (pleural, peritoneal and pericardial effusions) and preparation methods (conventional smears, liquid-based preparations and cell-blocks). Results: A total of 3633 cases were studied, 17 (0.5%) were diagnosed as ND, 1100 (30.3%) as NFM, 101 (2.8%) as AUS, 677 (18.6%) as SFM, and 1738 (47.8%) as MAL. The ROM for the categories were found to be 38.5%, 28.6%, 52.1%, 99.4% and 100%, respectively. The ROM for SFM was significantly higher than that for AUS (P < 0.001), while the difference between the ROMs for the IVa and IVb was insignificant. The sensitivity, negative predictive value(NPV) and diagnostic accuracy of liquid-based preparations were all superior to conventional smears and cell-blocks in detecting abnormalities. Using three preparation methods simultaneously had the highest sensitivity, NPV and diagnostic accuracy.Conclusion: Serous effusion cytology has a high specificity and positive predictive value(PPV), and the TIS is a user-friendly reporting system. Liquid-based preparations could improve the sensitivity of diagnosis, and it is best to use three different preparation methods simultaneously for serous effusion cytologic examination.

Comparison of Morphological Similarities and Differences between Liquid-Based Cytology and Conventional Techniques of Serous Effusion Cytology Specimens

<b><i>Introduction:</i></b> The aim of this study is to discover a fast and efficient method for the diagnosis of serous effusion cytology specimens by comparing the cytomorphological features of SurePath (SP) smears and smears prepared by cytospin. After the macroscopic features of the incoming material were recorded, it was divided into 2 for conventional technique (CT) and liquid-based technique. Cytospin was used for CT and SurePath for liquid-based technique in this study. <b><i>Materials and Methods:</i></b> 243 serous effusions (33 thoracentesis and 92 paracentesis fluids, 118 peritoneal lavage fluids) were investigated. After shaking the effusion gently, it was centrifuged for 5 min at 1,250 rpm for cytospin smear. SP smear was prepared according to the “BD PrepStain slide processor”. Two smears were prepared with these 2 methods and then stained with Papanicolaou. The smears were examined under a light microscope in terms of fixation, background, cellularity, nucleus, and structural features. All statistical analysis of the data was performed using the SPSS 17.0 software. For each microscopic feature, the χ² test was used to assess the significance of the relationship between cytospin and SP, and level of agreement in between the methods was assessed using the kappa statistic. <b><i>Results:</i></b> A statistically significant difference was observed between the 2 methods in background (<i>p</i> &#x3c; 0.001), cellularity (<i>p</i> &#x3c; 0.001), nucleus features (<i>p</i> &#x3c; 0.001), and structural features (<i>p</i> &#x3c; 0.05). There was no significant difference in fixation. Low level of agreement was observed with the kappa statistic in fixation, background, and cellularity. Moderate level of agreement was observed in the nucleus and structural feature groups with the kappa statistic. <b><i>Discussion/Conclusion:</i></b> Although there are advantages of liquid-based technique such as standardized fixation and cleaner background, since the cellular and background components required for morphological analysis and diagnosis are better preserved in cytospin, it is considered to be better to use liquid-based technique not alone but together with CT.

Molecular testing on serous effusion: An update

Cytological examination of the effusion fluid provides valuable information regarding the presence of malignancy. At times, it is challenging to diagnose malignant cells in serous effusion. The various ancillary techniques are available to solve the problem including immunocytochemistry, DNA ploidy, and multicolored flow cytometry. At present, the molecular tests on the effusion sample are of growing interest. The effusion sample is rich in cells and cell-free fluid that contains free DNA, cytokines, and extracellular vesicles. Molecular tests in effusion sample not only provide a diagnosis of malignancy but can also give valuable information that may be essential for the individualized therapy, management, and prognostic assessment. In this paper, we reviewed the application of the different molecular tests in the effusion sample.

Cellblockistry in serous effusion cytology- A systematic review with recent concepts

Serous effusion cytology being a minimally invasive, readily accessible and inexpensive diagnostic procedure. Nevertheless, the accuracy of SEC could vary widely due to the multitude factors including the level of experience of the cytologists Conventional smear has its own limitations with varied efficacy and hence warranting ancillary studies. Cell block has emerged as a paramount and robust platform for sample processing techniques in cytology. Research studies have proved that the efficiency of cytological diagnosis increases by significant margin of 15-20 percent when it is done in conjunction with cell block techniques especially in cases of exudative fluids in picking up crucial cases and based on this, we intended with a novel aim to analyse the accuracy of Serous effusion cytology by combining conventional smear and cell block technique with an attempt to assess the effectiveness of the cell block by our indigenous Modified Bouin’s method.Cell block method prepared by our indigenous Modified Bouin’s preparation with formalin fixative proved to show high quality significance and hence it could be followed in routine practice across laboratories. Cell block technique is quantitatively superior both standalone as well as in conjunction with conventional smear by improving the effective diagnosis of SEC. Diligent use of cell block technique eliminates the suspicious of malignant category on CS and thereby giving more definite diagnosis and thus it is mandated that combined approach of CB in conjunction with CS should be practiced as binary protocol which proved to have obvious influence on patient management.

MOC31 Immunostaining in the Diagnosis of Metastatic Adenocarcinoma in Serous Fluid: Special Emphasis on Atypical Cytological Cases

<b><i>Background:</i></b> The diagnosis of atypical cases in the effusion cytology sample often poses a challenge to the cytologists. <b><i>Aims and Objectives:</i></b> We evaluated the diagnostic role of MOC31 in the metastatic adenocarcinoma in effusion fluid. <b><i>Materials and Methods:</i></b> The cytological examination and MOC31 immunostaining in the cell block sections were carried out in 64 cases of serous effusion. A total of 23 cases showed atypical cytology, out of which suspicious for malignancy (SFM) and atypia of undetermined significance (AUS) were 19 and 4 cases, respectively. In these cases, we also performed calretinin immunostaining. The cytological features, results of MOC31 immunostaining, and follow-up data were correlated to find out the sensitivity and specificity of MOC31 immunostaining in the diagnosis of metastatic adenocarcinoma. <b><i>Result:</i></b> The sensitivity and specificity of MOC31 were 100%. MOC31 detected all the cases of metastatic adenocarcinoma. MOC31 showed strong positivity in 19 cases of SFM. All these cases had a malignant outcome in histopathology or follow-up data. In AUS cases, MOC31 immunostaining was negative with a benign outcome. In all the atypical but malignant cases calretinin stain showed diffuse cytoplasmic and nuclear positivity. In contrast, MOC31 showed strong membranous positivity and occasionally cytoplasmic positivity. <b><i>Conclusion:</i></b> MOC31 is an excellent marker of metastatic adenocarcinoma in the serous effusion. The membranous positivity of MOC31 and negative calretinin immuno­staining are helpful in atypical cytological cases to avoid the diagnostic dilemma. The MOC31 positivity is significantly useful in discrete atypical cells which are more challenging to recognize.