Effusion Fluid Cytology Research Articles

Salivary Duct Carcinoma Metastasis in the Pleural Fluid.

Salivary duct carcinoma (SDC) is a relatively rare, highly aggressive tumor with a poor prognosis that can be challenging to distinguish on cytology specimens. Awareness of the cytomorphologic and immunocytochemical findings is essential in arriving at a definitive diagnosis. This case report describes the primary diagnosis of a metastatic SDC on effusion fluid cytology.

Description Of The Results Of The Cytological Examination Of Pleural Fluid Using Giemsa Staining

Many objects after being fixed and then glued with entellan or balsam become so transparent that their structure is not obvious when viewed with a microscope. To overcome this difficulty, in general, preparations are colored with dyes that can clarify their structure. Staining aims to sharpen or clarify various tissue elements, especially the cells, so that they can be distinguished and studied under a microscope. This research was conducted at the Anatomical Pathology Laboratory of Grandmed Lubuk Pakam Hospital in February 2020 - July 2020. The research design was descriptive. The population of this study were all pleural effusion fluid cytology preparations at the Anatomical Pathology Laboratory of Grandmed Lubuk Pakam Hospital. The sampling technique used is accidental sampling, namely the technique of determining the sample by chance. In this case, the samples found were 16 samples. The results showed that microscopic images of pleural fluid cytology preparations using Giemsa staining showed poor (43.75%) and good (56.25%) results. The results of this study are expected to be input for the Anatomical Pathology Laboratory about the description of the results of the pleural fluid cytology examination using Giemsa staining to improve service quality.

Diagnostic Accuracy of Cell Block and Immunohistochemistry in Effusion Cytology.

Introduction Although the cytology of effusion fluids is considered a routine laboratory test, it has recently emerged as an essential tool in determining the primary site of origin of carcinoma of unknown primary. The sensitivity for diagnosing malignancy has enhanced with the inclusion of cytospin, cell block (CB), and immunohistochemistry (IHC) to effusion fluid cytology due to the improvement in morphological preservation and good cellular yield. The purpose of this study was to assess the diagnostic yield, sensitivity, specificity, positive predictive value, and negative predictive value of IHC and CB in effusion cytology. Methodology An institution-based cross-sectional study was conducted over a period of six months on 150 cases of effusion fluids submitted for diagnostic purposes. After the preparation of cytospin, the residual amount of centrifuged deposit was mixed with CytoLyt solution, thrombin, and plasma, and CBs were prepared. IHC was applied to the CB. Calretinin was used for mesothelial cells, and BerEP4, TTF-1, ER, WT-1, and CD-X2 were used for the confirmation and origin of malignant cells. Results The mean age of the patients was 51.75 ± 16.63 years. The male-to-female ratio was 1:1.24. Out of 150 cases, 78 were pleural effusions, 68 were peritoneal effusions, and four were pericardial effusions. Out of 150 cases, based on cytological examination alone, 66 (44%) were classified as benign, 27 (18%) as malignant, and 57 (38%) were suspicious for malignancy. When cytology was combined with CB and IHC, the diagnostic yield was increased to benign 95 (63.33%), malignant 48 (32%), and suspicious for malignancy 7 (4.67%). The most common cause of malignant pleural effusion was breast carcinoma in females and lung carcinoma in males. The most common primary tumor in malignant peritoneal effusion was ovarian carcinoma in females and colonic adenocarcinoma in males. The sensitivity and specificity of combined cytology with cell block and IHC were 92.31% and 98.95%, respectively. This combination produced significantly better results (p-value = 0.001) for detecting malignancy and reduced suspicious cases from 38% to 4%. Conclusion CB, in combination with IHC, increases the diagnostic yield and aids in detecting malignancy at an unknown primary site in effusion fluids. Both of these techniques can thus enhance the sensitivity and specificity of the diagnosis of effusion cytology. Hence, CB and IHC have advanced utility over cytological smears in effusion fluid cytological diagnosis.

Metastatic Carcinoma in Effusions.

Serous cavity may be involved by any neoplasm, including very rare examples of involvement by central nervous system tumors leading to a malignant effusion. The serous cavity lining is rich in lymphatics with lymphatic lacunae opening directly through narrow gaps (stoma) in the lining. Carcinomas mainly metastasize to serosa via the lymphatic vessels, which may be blocked leading to effusion. Primary carcinomas of organs such as lung, intestines, liver, ovary, etc., lined by serosal membranes may spread by direct extension, resulting in malignant effusions. As standard of practice, unless specified, cytopathologic examination of serous effusions implies detection of malignant cells.As compared to a surgical biopsy from a small focal area of an extensive serosal surface, effusion fluid from respective cavity exfoliates the cells from the entire serosal surface with minimal chance of sampling artifact. Because of this, effusion fluid cytology generally provides a higher diagnostic yield as compared to biopsy of the serous lining, as demonstrated by some studies. However, various challenges related to effusion fluid cytology makes the interpretation of effusion fluid cytology a field with potential misinterpretations, especially for those without proper experience or training.Developing and following a methodical approach is important for appropriate cytologic examination of effusion fluids. Proper approach may achieve definitive interpretation even without ancillary tests. However, lack of appropriate approach and processing may introduce a significant variation in interpretation due to combination of well-recognized diagnostic pitfalls, which may lead to lower reproducibility and even serious misinterpretations.Current review discusses in brief appropriate approach to processing and evaluating effusion fluid cytology for metastatic carcinoma. At general level, this is comparable to that of other specimens; however, it is critical to modify with reference to the limitations associated with effusion cytology.

The Indian Academy of Cytologists Guidelines for Reporting Serous Effusion (IACGRSE): An Interobserver Agreement Analysis.

Context:The Indian Academy of Cytologists published Guidelines and categories for Reporting Serous Effusions (IACGRSE) in 2020 to improve consistency and reproducibility of fluid cytology reporting and to guide patient management.Aims:To evaluate category-wise agreement while using IACGRSE 2020 categories. To analyze interobserver agreement among participants with different level of training and years of experience.Settings and Design:A retrospective interobserver variability study.Methods and Material:Study was done with four participants: an expert cytopathologist and three cytopathology fellows with varying experience. Fluid smears from 60 cases with clinical and/or radiological evidence of malignancy were categorized into one of the five IACGRSE 2020 categories. The interpretations of expert cytopathologist were taken as standard.Statistical Analysis Used:Interobserver agreement was analyzed using Kappa statistics.Results:Previous cases without definitive category got classified into “Atypical cells NOS” (3.33%) and “Atypical cells, Suspicious of Malignancy” (15%). Agreement analysis for IACGRSE 2020 categories showed better concordance for inadequate (I), malignant (V), and benign (II) categories. The range of Kappa for interobserver agreement of fellows was fair to substantial (range 0.1692–0.7249). The participant with substantial diagnostic agreement with expert (κ = 0.729, 88.3%) had the most experience. Causes of major discordance were pertaining to paucity and distribution of cells, and to misinterpretation of reactive mesothelial cells.Conclusions:IACGRSE 2020 categories and participants’ experience were important determinants in classifying the effusion fluid cytology smears and interobserver agreement; emphasizing the need to use IACGRSE2020, and sufficient time and training required for accurate diagnosis of fluid specimens.

Application of the Indian Academy of Cytologists Recommendations for Reporting Serous Fluid Cytopathology in Routine Reporting of Ascitic Fluid Specimen and Assessment of the Risk of Malignancy.

Background:A five-tiered reporting system for effusion fluid cytology has been published by the Indian Academy of Cytologists (IAC). Only a single study has evaluated the applicability of this system in routine reporting.Aims:We intend to evaluate the practical utility of this system in routine reporting of ascitic fluid cytology.Materials And Methods:Nine hundred and sixty-one cases of ascitic fluid cytology were included in this study. The clinical, radiological, cytomorphological, and follow-up data of these cases were reviewed. All cases were recategorized according to the proposed IAC system, and the risk of malignancy (ROM) for each category was estimated.Results:Age of the patients ranged from 1 to 92 years, and fluid volume ranged from 10 ml to 3 l. The number of cases included in each category and their respective ROM were as follows: category 1: 41, 21.42%; category 2: 805, 14.9%; category 3: 5, 33.3%; category 4: 31, 90%; and category 5:79, 96.4%.Conclusions:The new IAC guidelines for the serous fluid is representative, informative, and could be easily applied at our institutional level. We used the recommended diagnostic categories for reclassifying the ascitic fluid samples based on their cytosmear findings and conclude that the system has enormous utility at each level starting from the collection of fluid samples till the delivery of the report.

Effusion fluid cytology and COVID-19 infection.

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), which is responsible for coronavirus disease 2019 (COVID‐19), is known to cause severe respiratory infections with occasional accompanying pleural effusion (PE), pericardial effusion (PCE), or peritoneal effusion (PTE). The effect of COVID‐19 on effusion cytology is not yet known. This study aimed to examine the cytomorphologic features and workup of effusion fluids in patients with active COVID‐19 infection versus those in recovery.MethodsPE (n = 15), PCE (n = 1), and PTE samples (n = 20) from hospitalized patients with a SARS‐CoV‐2 infection (from June 1, 2020, to December 30, 2020) were reviewed. Effusion fluids with metastatic carcinoma were excluded. Differential cell counts, cytomorphology, and relevant immunostains for effusion fluids were retrospectively evaluated and compared between patients with active infection (positive on a SARS‐CoV‐2 nucleic acid amplification test [NAAT] within 2 months; n = 23) and those in the recovery phase from COVID‐19 (negative on a SARS‐CoV‐2 NAAT for >2 months; n = 13).ResultsThe cytology diagnoses were negative for malignancy (n = 31), atypical (n = 4), and suspicious for malignancy (n = 1). Active infection cases showed more atypical mesothelial cells than recovery cases (P < .05); some had enlarged nuclei, prominent nucleoli, occasional multinucleation, and bizarre nuclei. Immunostains were performed more often in active infection cases than recovery cases (47.8% vs 7.7%; P < .05). Differential cell counts (available for 28 cases) showed no significant differences between the active infection and recovery groups.ConclusionsThis study found atypical and bizarre mesothelial cells more often in effusions of cases with active COVID‐19 infection in comparison with patients in recovery. It is important for cytopathologists to become familiar with the cytomorphologic effects of SARS‐CoV‐2 on effusion cytology so that these cases can be properly triaged.

Diagnostic pitfalls in effusion fluid cytology.

Effusion fluid cytology has propensity for both false positives (in up to 0.5%) and false negatives (in up to 30%) results. Methodical approach from collection step to final interpretation stage could prevent both false positives and false negatives, if the interpreter is familiar with various factors responsible for diagnostic pitfalls in effusion fluid cytology. For this discussion, these factors are categorized as mentioned below: Surface tension-related alterations in cytomorphologyImproper specimen processingMany faces of reactive mesothelial cells, overlapping with those of cancer cellsProliferation-related featuresDegenerative changes, such as nuclear hyperchromasia and cytoplasmic vacuolationUnexpected patterns and unusual entities.

The panorama of different faces of mesothelial cells.

All effusions in serous cavities represent a pathologic processes secondary to inflammatory, neoplastic, hemodynamic, or mechanical/traumatic etiologies. This elicits reactive changes in the extremely sensitive mesothelial cells lining the serosal surfaces. The result is hypertrophy and hyperplasia which lead to broad changes with a wide range of morphological appearances. These reversible alterations may resolve entirely after the recovery of underlying pathology.Under the tertiary care situations, neoplastic effusion specimens are encountered more frequently. Although some non-neoplastic pathologic process may demonstrate a few diagnostic features, cytologic evaluation of malignant effusions usually show diagnostic malignant cells. However, the most versatile mesothelial cells demonstrate a very wide cytomorphological spectrum secondary to reactive challenges. These mesothelial cells are usually referred to as ‘reactive mesothelial cells’. In addition other terms such as reactive mesothelial proliferation, reactive mesothelial hyperplasia, irritated mesothelial cells, activated mesothelial cells, hyperplastic mesothelial cells, hypertrophic mesothelial cells, and proliferative mesothelial cells. Rarely atypical mesothelial cells, although not recommended, is used inadvertently. Although there is a lack of general agreement defining these terms, some of these including atypical mesothelial cells, should not be preferred. With reference to this CMAS series, usually favored term ‘reactive mesothelial cells’ is preferred.The size of reactive mesothelial cells range from 15 to 30 µm (but may be up to 50 µm). These polyhedral cells with variable amount of cytoplasm and enlarged nuclei may show variation in sizes and shapes with conspicuous nucleoli. Bi- and multi-nucleation is frequent. Cohesive groups of mesothelial cells as sheets and three dimensional groups may be present. Some floridly reactive mesothelial cells with hyperchromatic enlarged nuclei with prominent nucleoli and scant cytoplasm may resemble malignant cells. This astonishingly wide morphological spectrum of reactive mesothelial cells is a significant interpretation challenge in effusion fluid cytology. Methodical interpretation approach with appropriate knowledge about this wide spectrum is important aspect in diagnostic cytopathology of effusion fluids.

Approach to Diagnostic Cytopathology of Serous Effusions.

Collection of most serous fluids from various effusions is a relatively simple procedure. Because of this, serous fluids are commonly submitted for pathologic examination including cytopathologic evaluation by various clinical institutions. As a consequence, even a general pathology laboratory which may not have expertise with highly trained cytopathologist would be confronted with serous fluids for cytologic evaluation.However, cytopathologic evaluation of serous fluids is complex as compared to evaluation of fine needle aspiration cytology. This signifies the fact that all pathologists, irrespective of subspeciality cytopathology training and level of subspeciality expertise, should be conversant with the diagnostic challenges and pitfalls of effusion fluid cytology.Although, majority of effusions are due to reactive and non-neoplastic etiologies, cancer is one of the causes of an effusion as a manifestation of advanced cancer. Detecting neoplastic cells in effusion specimens in most of clinical settings is related to the advanced status of the disease, which usually is equivalent to incurable stage. Thus, interpretation of cytopathology as positive for cancer cell is highly critical in planning the trajectory of the clinical management with an obvious negative impact of false positive interpretation.Apart from cancer, effusions may be secondary to hemodynamic pathologies such as heart failure, hypoalbuminemia, cirrhosis etc. in addition to the different inflammatory conditions including parasitic infestations, bacterial, fungal, or viral infections, and other non-neoplastic etiologies including collagen diseases. Due to the cytomorphologic overlap of reactive mesothelial cells with malignant cells, general cytologic criteria for diagnosis of malignancy in single cells cannot be applied in most of the effusion specimens. This challenge is further amplified because of surface tension related phenomenon which ‘round up’ the cells after exfoliation in serous fluids. As a result, the native shapes of cancer cells cannot be a guiding feature. Thus the cytomorphologic features of cancer cells in serous fluids may not be same as seen in routine cytopathology of exfoliative, brushing, and fine-needle aspiration specimens.The cancer cells may continue to proliferate after exfoliation in the nutrient rich effusion fluids and may form proliferation spheres. It is crucial to consider these factors when interpreting effusion cytology. Amongst malignant effusions, adenocarcinomas are the most common cause of metastatic cancers, but almost any type of malignancy including melanomas, hematopoietic neoplasms, sarcomas, and mesotheliomas may involve serous cavities. The interpreter must be aware of the wide range of the cytomorphologic appearances of reactive mesothelial cells in effusion fluids. It is essential to understand these and other nuances related to effusion fluid cytology. Understanding potential pitfalls during various stages from processing to application of ancillary studies would increase the diagnostic accuracy and minimize atypical interpretations and false positivity.

Effusion Fluid Cytology and COVID-19 Infection

Effusion Fluid Cytology and COVID-19 Infection

Evaluation of immunohistochemistry staining and cytologic diagnosis by using cell block sections prepared with effusion fluid cytology specimens

To study the values of immunohistochemistry staining and cytological diagnosis by using cell block sections prepared with the effusion fluid cytology specimens. Ninety-nine effusion cytology specimens with the diagnoses of reactive mesothelial hyperplasia, atypical cells and metastatic carcinoma were enrolled into the study. The cytospin preparations/smears, cell block sections and immunohistochemical study were performed and correlated with the clinical findings and follow-up data. Amongst the 99 cases studied, the percentage with positive diagnosis using cytospin preparations/smears was 68.7% (68/99). The percentages with negative and equivocal diagnoses were 16.2% (16/99) and 15.1% (15/99), respectively. As for cell block sections, the percentages were 71.7% (71/99), 16.2% (16/99) and 12.1% (12/99), respectively. On the other hands, the percentages became 76.8% (76/99), 20.2% (20/99) and 3.0% (3/99), respectively, when coupled with immunohistochemical findings. The overall percentages of positive, negative and equivocal diagnoses were 77.8% (77/99), 17.2% (17/99) and 5.0% (5/99), respectively, upon clinicopathologic correlation. The difference between cytospin preparations/smears and cell block sections was not statistically significant (P > 0.05). When coupled with immunohistochemical findings or clinicopathologic correlation, the difference in rates of equivocal diagnosis however carried statistical significance (P < 0.05). The false-negative rate of immunohistochemical study applied on cell block sections was 1.0% (1/99). Immunohistochemistry, when applied on cell block sections, is useful in delineation of the primary origins of the tumor cells in effusion fluid cytology specimens. Combination of morphologic examination, immunohistochemical findings and clinicopathologic correlation can further improve the rate of positive diagnosis.

Significance of intercellular spaces (windows) in effusion fluid cytology: A study of 46 samples

The presence and nature of intercellular windows were studied on 46 body cavity fluid samples chosen on the basis of an unequivocal diagnosis on May-Grünwald-Giemsa (MGG)/Papanicolaou-stained smears and cell blocks. Of these, 24 cases had adenocarcinoma (AC) and seven had reactive mesothelium (RM) with 15 having distinct populations of both. Mucicarmine and PAS stains were used wherever indicated. The specificity of windows for predicting reactive mesothelium was evaluated. Intercellular windows were found in all cases of reactive mesothelium coinciding with the presence of the fuzzy peripheral microvillous borders. Surprisingly, as many as 17/39 (44%) of the adenocarcinomas also exhibited this feature, of which 13 had a distinctly visible evenly distributed ciliated cell membrane. In addition, 30/39 (77%) cases of AC exhibited a "window-like" appearance caused by cytoplasmic vacuolation. None of the adenocarcinoma clusters with true window formation showed positivity for the mucin stains, whereas all the clusters with pseudowindows caused by vacuolation were stained. Thus the specificity of intercellular windows for RM was merely 56%, though the sensitivity was 100%. On the other hand, the absence of windows was 100% specific for adenocarcinoma. Intercellular windows, though a feature of reactive mesothelial cell populations, can also be found in cases of ciliated adenocarcinomas and may not have a significant predictive value.

Thyroid transcription factor-1 is highly sensitive and specific in differentiating metastatic pulmonary from extrapulmonary adenocarcinoma in effusion fluid cytology specimens.

Thyroid transcription factor-1 (TTF-1) is a homeodomain-containing transcription factor selectively expressed in thyroid, lung and diencephalon. It has been shown to label pulmonary adenocarcinoma, thyroid tumors, and small cell carcinoma (pulmonary and extrapulmonary) with relatively high sensitivity and specificity. The usefulness of this immunostain in cytology specimens has not been thoroughly discussed in the literature. The authors evaluated 36 effusion cytology cases (17 pleural effusion, 18 ascitic fluid, and 1 pericardial effusion) diagnosed as metastatic adenocarcinoma and with cell blocks prepared from the file of Pamela Youde Nethersole Eastern Hospital, Hong Kong, during a three-year period from 1998 to early 2001. The clinical, radiologic, cytologic, and histologic (if any) findings were reviewed. A provisional diagnosis of the primary site was deduced for each of the 36 cases by clinical, radiologic, and/or histologic correlation. Immunohistochemical study was performed on the cell block sections of the effusion cytology specimens using mouse monoclonal antibody against TTF-1, after microwave heat-antigen retrieval. The results were correlated with the primary origin of the metastatic adenocarcinoma. Among the 17 cases of metastatic pulmonary adenocarcinoma, 15 cases showed nuclear staining for TTF-1 in most of the tumor cells (sensitivity, 88.2%). None of the 19 cases of metastatic extrapulmonary adenocarcinoma expressed TTF-1 (specificity, 100%). The current study validates TTF-1 as a highly sensitive and specific immunomarker for distinguishing between metastatic pulmonary and extrapulmonary adenocarcinoma in effusion cytology specimens, which are known to be associated with intrinsic artifact due to less than ideal cellular preservation.

Effusion fluid cytology of lymphomas - the Hong Kong experience

Among the 259 effusion fluia cytological specimens received from 62 cases of histologically proven lymphoma, 168 (62.5%) were diagnostic of lymphoma Infiltration. The relative incidence of different histological types and their occurence In different sites were analysed. We attempted to classify these cases cytologlcally by analysing cellularlty, nuclear features, chromatin pattern and presence of nucleoli. Correlation with the histological classification using the International Working Formulation (WF) was performed. None of the diagnostic specimens were Hodgkin's disease and only three cases were follicular lymphomas. Most of the specimens (40.7%) were from cases of diffuse, predominantly large cell. The other types Include lymphoblastic (27.2%), diffuse mixed small cleaved and large cell (9.2%), diffuse predominantly small cleaved cell (8%), immunoblastlc (3.1%), small lymphocytic (0.6%), and unclassified (8%). Lymphoblastic lymphomas more commonly involved the pleura. Cytologlcal classification predicted the histological subtype correctly In 82.7% of the diffuse lymphomas. We conclude that effusion fluid cytology is most helpful In recognising body cavity involvement by high grade lymphomas. Correlation between cytologlcal and histological classification was high, partly because most of the cases were diffuse non-Hodgkln's lymphomas.