Cell Block Preparation Research Articles

Single-cell multiplex immunocytochemistry in cell block preparations of metastatic breast cancer confirms sensitivity of GATA-binding protein 3 over gross cystic disease fluid protein 15 and mammaglobin.

Metastatic breast cancers are frequently encountered in cytology and require immunocytochemistry (ICC). In this study, traditional and multiplex ICC (mICC) for GATA-binding protein 3 (GATA3), gross cystic disease fluid protein 15 (GCDFP15), and mammaglobin (MMG) were performed with the aim of validating mICC in cell blocks, with further single-cell expression pattern analysis to identify the single markers and combinations of markers most sensitive in subtypes of breast cancer. GATA3, GCDFP15, and MMG were paired with OptiView 3,3'-diaminobenzidine and Ventana DISCOVERY Purple and Blue, respectively, with cyclical and serial staining. Bright-field imaging was performed with the Mantra 2 system and analyzed with the inForm Tissue Finder (Akoya Biosciences). Cell detection and phenotyping were further confirmed by two pathologists. In the 36 cases studied, traditional ICC and mICC demonstrated good concordance (kappa coefficient, >0.5; p<.01) at three cutoffs (1%, 5%, and 50%), except for GATA3 at the 1% cutoff. Single-marker positivity outnumbered double-marker positivity and the exceedingly rare triple-marker positivity (<3%). GATA3 was the leading single marker-positive phenotype in all breast cancer subtypes, except for MMG in estrogen receptor-positive, progesterone receptor-positive, and human epidermal growth factor receptor 2-positive (ER+/PR+/HER2+) breast cancers. Limited to two markers, GATA3/MMG included the greatest number of tumor cells for luminal breast cancers (ER+/PR+/HER2+, 60.6%; ER+/PR+/HER2+, 31.4%), whereas HER2-overexpressed breast cancers (27.4%) and triple-negative breast cancers (26.4%) favored the combination of GATA3/GCDFP15. For a single marker, GATA3 displayed the highest sensitivity. The addition of MMG for hormone receptor-positive breast cancers and GCDFP15 for hormone receptor-negative breast cancers further increased sensitivity. The low proportion of multimarker-positive cells suggested that the coexpression observed with traditional ICC is attributable to intratumoral heterogeneity, not genuine coexpression.

Tools, techniques, and challenges in preparing cytology specimens for ancillary studies: results of the ASC Optimizing Cytology and Small Biopsy Specimen Processing for Ancillary Studies Task Force survey

IntroductionAncillary testing on cytopathology and other small biopsy specimens is crucial for diagnosis and provides critical information to clinicians. Testing is dependent on pre-analytic factors and would benefit from standardization of specimen collection protocols across laboratories. To assess institutional practices and areas of need for evidence-based standards, we surveyed current practices across cytopathology laboratories. Materials and MethodsA twelve-question electronic survey was distributed to American Society of Cytopathology (ASC) members through email, social media, and the ASC from January 8th to March 1, 2024. Survey responses were tabulated. ResultsOf 294 respondents, 257 (87%) completed at least 10/12 questions. Formalin-fixed, paraffin-embedded cell blocks (CB) are utilized for immunohistochemistry, molecular testing, and in situ hybridization by 89%, 84%, and 71% of respondents, respectively. For fine needle aspirations, no collection medium is utilized by a majority of respondents. In contrast, 61% utilize no collection medium for fluids; 64% predominantly utilize liquid-based preservatives for other exfoliative specimens. For CB preparation, 58% of respondents use coagulating agent; 67% use no fixative before formalin. The two most significant factors limiting clinical utility of ancillary testing in cytology specimens are low cellularity and lack of validation (49% and 23% of respondents, respectively). ConclusionsThere is wide variation in current practices among laboratories, reflecting lack of consensus. Although laboratories utilize different collection media for different specimen types, for CB utilization, current survey results are similar to those reported previously. ASC has convened a task force to facilitate specimen standardization and minimize variability among pre-analytic factors.

A Comparative Study of Sodium Alginate and Plasma Thrombin Cell Block in Diagnostic Cytopathology.

Background: Cell block is an indispensable supplement in the practice of cytopathology. The diagnostic utility of cytology specimens is significantly impacted by the capacity to generate sufficient cell blocks obtained from concentrated fluid samples or fine-needle aspiration specimens after routine processing. This routine processing involves getting directed passes to produce a cell block, especially if the cytopathologist believes additional immunocytochemical stains and/or molecular studies would be required. Objective: This study compared two methods of cell block preparation: the sodium alginate (SA) method and the plasma thrombin (PT) method. A comparison was made regarding overall cellularity, morphological preservation, and concealed artifacts. Methodology: This cross-sectional study evaluated 104 serous fluid samples and fine-needle aspirates. Cell blocks were prepared for each sample using the plasma thrombin and sodium alginate technique. The formalin-fixed, paraffin-embedded cell blocks were subjected to histochemical staining with hematoxylin and eosin, and slides were assessed for cellularity, artifacts, and morphological preservation. Results: The study utilized chi-square tests to analyze cellularity, morphology, and artifact presence, demonstrating significant differences in cellularity and artifacts between the two methods, with the sodium alginate method showing more cellularity and more artifacts, while morphologically, there was no significantdifference between the two methods. Conclusion: Our study's findings have practical implications for cytopathologists. We conclude that, compared to plasma thrombin methodology, the sodium alginate cell block technique yields higher cellularity, while there was no difference in morphology. Even though artifacts were more prevalent in sodium alginate cell blocks than in plasma thrombin cell blocks, our study suggests that the former can be a better alternative for cell block examination.

Comparison of the accuracy of minimally invasive techniques (cytology, cell block, immunocytochemistry and clonality assay) in the diagnosis of canine multicentric lymphoma

Lymphoma ranks among the most prevalent neoplasms in veterinary oncology, frequently diagnosed in dogs, particularly in its multicentric form. While histopathology plays a crucial role in lymphoma diagnosis, prognosis and prediction of biological behavior, minimally invasive diagnostic methods are increasingly emerging as viable alternatives. This study aims to assess and compare various minimally invasive diagnostic techniques for multicentric lymphomas in dogs. A total of 38 dogs, encompassing various sexes, ages, and breeds, with clinical suspicion of multicentric lymphoma, was included in the study. Fine needle aspiration was employed to collect samples from lymph nodes, which were subsequently used for cytology, cell block preparation, PCR for antigen receptor rearrangement (PARR), and immunocytochemistry. Among the animals evaluated, 31 dogs received a cytological diagnosis of lymphoma, while 7 showed findings suggestive of lymphoma or lymphadenitis. Immunocytochemistry on cytological smears yielded inconclusive results in 50 % of cases, with 44.74 % diagnosed with B-cell lymphoma and 5.26 % with T-cell lymphoma. Cell block analysis identified lymphoma in 30 dogs and suggested lymphoma or a round cell neoplasm in 8 cases. Cell block immunocytochemistry confirmed lymphoma in 35 dogs, comprising 80 % B-cell and 20 % T-cell lymphomas. PARR revealed monoclonal rearrangement/clonality in 33 cases, with 84.85 % of these being B-cell and 15.15 % T-cell lymphomas. This study underscores the precision of minimally invasive techniques in diagnosing and characterizing multicentric lymphoma in dogs, reaffirming their significance in veterinary clinical practice.

Diagnostic and Predictive Immunocytochemistry in Lung Cancer

Background Immunocytochemistry (ICC) is suitable for use on a range of cytology preparations, such as cell blocks, air-dried slides, ethanol-fixed slides, direct smears, cytospins, and liquid-based cytology (LBC) samples. However, it must be standardized against the gold standard of formalin-fixed paraffin-embedded tissues with adequate number of positive and negative controls. The role of ICC in lung cancer is crucial, as most lung cancer specimens are cytology samples. Accurate diagnosis and testing of certain biomarkers rely heavily on both diagnostic and predictive ICC. Summary Key ICC markers important in lung cancer include, but are not limited to, diagnostic ICCs such as TTF-1, p40, Napsin A, and p63, as well as predictive ICCs like ALK, ROS-1, PD-L1, and NTRK. Key Messages With proper validation, immunocytochemistry for lung cancer can be effectively performed on direct smears, cytospins, and other specimens, even when resources for preparing cell blocks are unavailable. This is particularly true for diagnostic antibodies, but it is important to exercise caution with predictive immunocytochemistry. Nonetheless, a low threshold for molecular testing should be maintained. PD-L1 ICC can be challenging and should ideally be performed on formalin-fixed cell blocks or biopsies when available.

Comparison of Claudin-4, BerEP4, Carcinoembryonic Antigen and MOC31 in Serous Fluids Metastases Demonstrate High Sensitivity of Claudin-4 at Low Cellularity.

Claudin-4 has been described as a highly sensitive immunocytochemical marker for detection of metastatic carcinoma cells in effusion cytology specimens. This study aims to challenge the performance of claudin-4 in different types of malignancies and low cellularity specimens, by comparison with other markers in a large cohort of carcinomatous effusion specimens. Cell block preparations from peritoneal and pleural fluid specimens were retrieved, with malignant (carcinoma) diagnoses confirmed by review of hospital diagnosis code and pathology reports. Claudin-4, BerEP4, CEA, and MOC31 immunocytochemistry were performed and scored by expression proportion and intensity. Tumor cellularity was assessed for subgroup analysis of low cellularity specimens. Totally 147 specimens (70 pleural, 77 peritoneal) of 68 lung, 62 breast, 9 gynecological, and 7 gastrointestinal carcinomas were retrieved. The average proportion expression of claudin-4 was highest (89.6%, vs. CEA 40.5%, BerEp4 18.6%, MOC31 16.8%) and the percentage of strong expression was highest for claudin-4 (72.1%). Expression levels of claudin-4 were consistently higher than other markers in subgroups of all primary sites. The difference was more significant for low cellularity specimens. High (≥50%) proportion expression was seen for 96.61% of cases for claudin-4 (vs. BerEp4 8.77%, CEA 46.55%, MOC31 8.77%, p < 0.001). These factors contributed to a low concordance between claudin-4 and BerEp4, CEA and MOC31 (K = 0.010-0.043). Claudin-4 is more sensitive than CEA, BerEp4 and MOC31, suitable for low cellularity specimens of most types of metastatic carcinoma and is a robust immunocytochemical marker for carcinoma that can be used solitarily.

Application of cell blocks to assist in precise cytological diagnosis of serous effusion

Objective: To investigate the importance of cell block and immunohistochemistry in the accurate diagnosis of serous effusion. Methods: A retrospective study was conducted on 3 124 cases of serous effusion from the Department of Pathology, Beijing Hospital from 2018 to 2022, include 2 213 cases of pleural effusion, 768 cases of peritoneal effusion, 143 cases of pericardial effusion. There were 1 699 males (54.4%) and 1 425 females (45.6%), average age 69 years old. Of which 1 292 cases were prepared with cell blocks and examined with immunohistochemical stain. Results: The percentage of malignant diagnosis increased from 64.9% (839/1 292) to 84.0% (1 086/1 292) after cell block preparation, and 1 086 cases were accurately diagnosed with histological type and/or origin of primary tumor. The undetermined diagnosis of suspected malignancy decreased from 13.3% (172/1 292) to 0.1% (1/1 292) and that of atypical hyperplasia from 18.8% (243/1 292) to 0.4% (5/1 292). The negative result for malignancy rate increased from 3.0% (38/1 292) to 15.5% (200/1 292). The differences highlighted above were statistically significant (Pearson's chi-squared test=12.739, P<0.01). Conclusion: Application of immunohistochemistry based on cell block can significantly improve malignant diagnosis in serous effusion, identify tumor origin and histological type as well as decrease the uncertain diagnosis.

Diagnostic utility of transfer learning by using convolutional neural network for cytological diagnosis of malignant effusions.

Cytological analysis of effusion specimens provides critical information regarding the diagnosis and staging of malignancies, thus guiding their treatment and subsequent monitoring. Keeping in view the challenges encountered in the morphological interpretation, we explored convolutional neural networks (CNNs) as an important tool for the cytological diagnosis of malignant effusions. A retrospective review of patients at our institute, over 3.5 years yielded a dataset of 342 effusion samples and 518 images with known diagnoses. Cytological examination and cell block preparation were performed to establish correlation with the gold standard, histopathology. We developed a deep learning model using PyTorch, fine-tuned it on a labelled dataset, and evaluated its diagnostic performance using test samples. The model exhibited encouraging results in the distinction of benign and malignant effusions with area under curve (AUC) of 0.8674, F-measure or F1 score which denotes the harmonic mean of precision and recall, to be 0.8678 thus, demonstrating optimal accuracy of our CNN model. The study highlights the promising potential of transfer learning in enhancing the clinical pathology laboratory efficiency when dealing with malignant effusions.

The diagnostic utility of cell block as an adjunct to routine cytology

Despite the diagnostic utility of cell block in FNAC and fluid cytology, known for better cellular yield and improved diagnostic accuracy, the technique remains to be underutilized for diagnosing neoplastic lesions.In this paper, a hospital based prospective study of 195 samples was conducted on cytological samples with the aim (a) to evaluate the diagnostic utility of cell block as an adjunct to routine cytological evaluation of aspiration and effusion fluid specimens, (b) To correlate the findings of routine cytology, cell block and routine histopathological examination wherever possible and (c) to explore the possibility of using ancillary techniques such as immunohistochemistry on cell blocks. The study revealed, most of the patients were between 51- 60 years with female preponderance. Among 195 samples, 79 (40.5%) were peritoneal fluids and 85 (43.5%) were lymph node. The diagnosis on conventional smear and cell block showed 71 (36.5%) cases and 68 (35%) cases were negative for malignancy respectively. 6 (3%) cases and 4 (2%) cases were suspicious for malignancy respectively. 118 (60.5%) cases and 123 (63%) cases were positive for malignancy respectively. Amongst the peritoneal effusion the most common primary site was ovary whereas majority of the primary site was unknown in lymph node FNAC. Peritoneal effusion showed 8 additional cases as positive for malignancy in CB preparation which were negative or suspicious for malignancy on CS. In FNAC, two additional positive case was found in CB preparation of lymph node. A Kappa value of 89.5 % for statistical correlation between Conventional smear and cell block preparation was calculated. The use of Cell block technique increases the detection of malignancy when used as an adjunct to conventional smears. Cell block technique is simple, inexpensive and reliable adjuvant to smears and it is recommended for routine cytological diagnosis and for application of immunomarkers and molecular studies.

Cell Block: An Unsung Hero

Although present since historic times, cell blocks have still been on a back seat when it comes to diagnostics, despite having immense potential. Cell block preparations made from sedimented cells can be a useful adjunct to routine cytological methods. We, thus, present a case of a 76-year-old female who would have not been treated on time, if a cell block hadn’t been attempted.

Infections associated with haemophagocytic syndrome: A case report of a rare coexistence with common infections

Infection-associated haemophagocytic syndrome (IAHS) is exceptional in typhoid and tuberculosis co-infections. We encountered a 50-year-old man with a history of pacemaker implantation who was previously treated for typhoid fever and currently presented with a chronic fever and shortness of breath. Initial laboratory tests revealed pancytopenia. A bone marrow aspiration was performed. However, due to cardiac problems, a bone marrow biopsy could not be performed. A bone marrow aspirate was submitted for cell block preparation. The cytology of the bone marrow aspirate revealed hemophagocytosis, which was initially presumed to be secondary to typhoid. Subsequently, cell block preparation of the bone marrow aspirate exhibited numerous granulomas with necrosis suggestive of tuberculosis. The patient was successfully treated with anti-tuberculosis drugs, steroids, and antibiotics. This case highlighted an association between IAHS and a common tropical illness. The usefulness of an aspirate cell block in the absence of biopsy and the potential existence of tuberculosis, especially in tuberculosis-endemic countries is to be noted.

Rapid on-site evaluation and cell blocks: getting the most from the least invasive method in cytopathology

Fine needle aspiration cytology (FNAC) sampling is a minimally invasive procedure done to identify the pathology behind superficial and deep-seated lesions. Rapid on-site evaluation (ROSE) can be an adjunct to the FNACs. Our study aimed to identify the role of ROSE in diagnostic adequacy and to check the benefit of cell block (CB)/cell buttons prepared from the ROSE samples. A prospective study was conducted where all patients referred for FNAC were included. ROSE using 1% aqueous toluidine blue stain and CB/cell button preparations were done for the identification of various cytological lesions. Among 600 cases included in the study most common age group was third and fourth decades with a mean age of 41.6 years and M: F ratio of 1:1.7. Ultrasound-guided procedures were done in 20% of cases. CB preparation was available in 14% of cases. Most CBs were from the cases wherein ROSE was performed 81% (77 out of 86), with CB helping in making an accurate diagnosis in 17% of cases. Lymph nodes 26%, and thyroid 23% were the most common sites for sampling with the highest number of repeat procedures from non-ROSE cases (14%). The non-diagnostic rate for non-ROSE cases was 7.7% (23/300) even after the repeat procedures as compared to 1.3% (4/300) for ROSE. Three slides on average were consumed in ROSE-performed procedures, as compared to an average of 5 slides in non-ROSE. The average turnaround time was 1.7 days for non-ROSE cases and 1.05 for ROSE cases respectively. Cyto-histopathological correlation was available in 40% of cases with a sensitivity of 98.1%, specificity of 96.7%, positive predictive value of 90%, negative predictive value of 99.4%, and diagnostic accuracy of 97%. The correlation of CB, number of slides consumed, and turnaround time among the 2 groups were statistically significant (P value < 0.001). ROSE is a method used to assess material aspirated at the time of FNAC procedures to determine the adequacy and to an extent to identify whether the lesion is neoplastic or non-neoplastic. CBs have helped in increasing diagnostic accuracy apart from the fact that the paraffin-embedded tissue material can be used for further studies.

Utility of the United Kingdom National Health Services Breast Screening Program Diagnostic Protocol in Fine-needle Aspiration Cytology with Cell Block Preparation in Cases of Palpable Breast Lumps: A Reliable, Fast, and Accurate Diagnostic Method for the Assessment of Breast Lumps with Histopathologic Correlation.

A palpable breast lump is a common diagnostic problem for clinicians and surgeons. Fine-needle aspiration cytology (FNAC) has many advantages such as less cost, less sample processing time, less pain, less chance of hematoma, and less discomfort. FNAC with cell block preparation further increased both sensitivity and specificity by nearly 100%. With the cell block preparation, we can also use newer tests like estrogen receptor-progesterone receptor-human epidermal growth factor receptor 2. The aim of this study was to derive conclusions about the correlation, including sensitivity, specificity, positive and negative predictive values (NPVs), and the diagnostic accuracy of FNAC, with or without cell blocks, compared to the final histopathology in cases of palpable breast masses. A cross-sectional prospective study was conducted after getting approval from the Human Ethics Research Committee from January 2018 to December 2019, which included 65 patients. Patients diagnosed clinically for breast lumps who underwent diagnostic FNAC with cell block, followed by a histopathological examination at our hospital, were included in the study. FNAC without cell block sensitivity, specificity, positive predictive value (PPV), NPV, efficiency rate, and diagnostic accuracy are 91.3%, 100%, 100%, 90.1%, 86.2%, and 96.5%, respectively. FNAC with cell block sensitivity, specificity, PPV, NPV, efficiency rate, and diagnostic accuracy are all 100%. All of our results beat the standard estimate. Fine-needle aspiration cytology is a patient-friendly, easy, reliable, repeatable, and simple diagnostic test. Whenever it is combined with cell block preparation, improves the accuracy of FNAC diagnosis which is more accurate and comparable to golden-standard biopsy with histopathology examination.

Concordance between conventional cytology and cell block of suspected malignant pleural effusion: A record-based study in a tertiary care center of eastern India

Background: Cytological study of pleural fluid helps establishing the underlying cause of pleural effusion. It is considered the most important tool in diagnosing malignancy in effusions. However, accurate identification of cellular morphology can be a problem in conventional cytology. Cell block preparation from pleural effusion aids in this diagnosis due to the preservation of tissue architecture, and multiple sections can be obtained for further studies. Aims and Objectives: The objectives of this study were to compare the diagnostic results of conventional cytology and cell block studies of suspected malignant pleural effusions and find out the diagnostic agreement or concordance between the two methods. Materials and Methods: A record-based study was conducted at the Department of Pathology on conventional cytology and cell block study reports of 150 suspected malignant pleural effusion cases over 35 months. The diagnoses were expressed in five categories – non-diagnostic, negative for malignancy, atypia of undetermined significance, suspicious for malignancy, and malignant. χ2 test was used to identify the percentage of malignancy reported. Agreement of both methods was assessed through Kappa statistics. Results: About 4.67% of cases were reported as malignant by conventional cytology, whereas cell block study diagnosed malignancy in 19.33% of cases. Relative diagnostic agreement between the two methods was 0.73 and concordance by Cohen’s Kappa was 0.34, which signifies fair concordance. Conclusion: Cell block study, though having a fair concordance, is much superior to conventional cytology smears in detecting malignant cells and diagnosing a pleural effusion as malignant.

Strongyloides stercoralis infection masquerading as malignant ascites in a case of angiosarcoma.

Strongyloides stercoralis is a parasitic nematode that infects millions of people worldwide. It primarily infects humans but can also be found in domestic animals and primates. The severity of infection varies from asymptomatic to life-threatening complications. We present a case of a 56-year-old male with a known case of angiosarcoma liver with massive ascites and low-grade fever. He was clinically diagnosed as having malignant ascites and was planned for chemotherapy. During therapeutic cum diagnostic ascitic tap, cell block sections revealed the presence of cross sections of nematode S. stercoralis gravid uterus with eggs. Later, stool for ova and cysts also revealed multiple larval forms of the nematode. S. stercoralis hyperinfection is often accompanied by sepsis or meningitis with enteric organisms. Patient was started on tab. ivermectin 12 mg once a day for two days (in the standard dosage of 200 mcg/kg) was then repeated in the same dosage for another two days after two weeks, and gradually the ascites settled. Post-treatment ascitic tap cell block preparations did not show any parasites. Patient has been on follow-up for 6 months, and he remains asymptomatic.

A96 A QUALITY ASSESSMENT STUDY TO DETERMINE IF TISSUE ACQUISTION AND SPECIMEN HANDLING IMPACT THE DIAGNOSTIC YIELD OF ENDOSCOPIC ULTRASOUND-GUIDED FINE NEEDLE ASPIRATION OF SOLID MASS

Abstract Background Endoscopic ultrasound (EUS)-guided fine needle aspiration biopsy (FNAB) of solid mass lesions has a sensitivity and specificity between 50-100%. Tissue acquisition and specimen handling are factors that may contribute to this variability. At our institution, 3 endoscopists perform EUS. The aspirated material obtained is expressed onto slides for cytology (prepared by a nurse) and solid tissue fragments transferred into formalin. At the discretion of the endoscopist, aspirated material is collected in saline for cell block preparation. Aims To assess the impact of tissue collection and specimen handling on diagnostic yield of EUS-FNAB of solid mass lesions. Methods A chart audit was completed for all patients undergoing EUS-FNAB of solid mass lesions between January 1, 2022 and December 31, 2022. Descriptive statistics were completed. A definite diagnosis was considered when calculating the diagnostic yield. Results A total of 184 patients (100 M, 84 F), mean age 64±13 years (range 14-89 years), underwent 200 EUS-FNABs by 3 endoscopists. Pancreatic masses were the most common indication in 118/200 (59%) cases. A 22-gauge FNAB needle was used in 189/200 (95%) cases. A total of 285 needle passes were performed in 149 cases (mean 1.9/case). In the remaining 51 cases (26%), the number of needle passes was not specified. Tissue samples were transported in formalin in 190 cases, on cytology slides in 170 cases, and in saline for cell block preparation in 41 cases. Overall, a definite diagnosis was achieved in 149/200 cases (75%). Stratifying for needle passes, a definite diagnosis was achieved in 22/39 (56%), 71/85 (84%), 20/24 (83%), and 1/1 (100%) cases that had 1, 2, 3, and 4 needle passes. Of the 51 cases with unspecified needle passes, a definite diagnosis was achieved in 35 cases (69%). The diagnostic yield obtained with saline for cell block was similar to that obtained with formalin and cytology slides (30/41 [73%] vs. 144/190 [76%] and 132/170 [78%]). Conclusions Increasing the minimum number of needles passes for tissue acquisition to 3 per case may increase the diagnostic yield of EUS-FNAB. Documenting the number of needles passes in the endoscopy report is an important quality indicator. Cytology slides and tissue in formalin should be considered standard of care but aspirated material should continue to be used for cell block preparation. However, there is some concern that saline as a transport medium may de-vitalize the aspirated material, so it should be replaced with formalin to preserve tissue integrity. Funding Agencies None

Cell block practices in European cytopathology laboratories.

There are numerous methods and procedures described for the preparation of cell blocks (CBs) from cytological samples. The objective of this study was to determine current practices and issues with CBs in European laboratories. A link to an online survey, with 11 questions about CB practices, was distributed to cytology laboratories via participants of United Kingdom National External Quality Assurance Service for Cellular Pathology Techniques and national representatives in the European Federation of Cytology Societies. A total of 402 laboratories responded completely (337/402, 84%) or partially (65/402, 16%) to the survey by February 4, 2022. The most common CB practice is embedding cell pellets using plasma and thrombin (23.3%), agar (17.1%), Shandon/Epredia Cytoblock (11.4%), HistoGel (7.9%), and Cellient (3.5%). Other methods such as CytoFoam, albumin, gelatin, Cytomatrix, and collodion bags are rarely used (1.0%, 0.7%, 0.7%, 0.3%, and 0.2%, respectively). CBs are also prepared from naturally occurring clots or tissue fragments (29.5%) and cells scraped from unstained or prestained smears (4.4%). The most frequent issues with the CBs in a daily cytology practice are low cellularity (248/402, 62%) and dispersed cells (89/402, 22%), regardless of the CBs preparation method or how the samples for embedding were selected. There is a great variability in CB practices in European laboratories with low cellular CBs as the main issue. Additional studies are mandatory to evaluate and improve performance and cellular yield of CBs.

Contemporary art of cell-block preparation: Overview.

Cell blocks (CBs) are paraffin-embedded versions of cytology specimens. These versions are contrasted with tissues made from surgical pathology specimens of formalin-fixed paraffin-embedded (FFPE) tissue. CBs enable various elective ancillary studies of a range of specimens. These studies include the potential to perform molecular tests with the enhanced cytopathological interpretation. CBs are increasingly reported in cytology specimens. The enhanced role of CBs incorporates additives with new markers for immunohistochemistry (IHC), including the multicolored approach to IHC, and the subtractive coordinate immunoreactivity pattern. Even when archived material is retrospectively retrieved, CBs are a major tissue source for many supplementary studies. The CBs have been qualitatively and quantitatively improved. CBs are significant since they have increased molecular markers standardized on FFPE tissue. High-quality CBs can serve as useful additions to cytological smear preparations and touch imprint cytology. Most cytological specimens, such as fine-needle aspirations, cavitary effusion, washings, brushings, and gynecological and non-gynecological liquid specimens, may be used to produce CBs. This review deals with the CB-making process and discusses various historical limitations with an emphasis on recent advances.

Utility of guided FNAC and cell block preparation from liver and gall bladder masses: Learning experience from a tertiary care center.

Ultrasound- and CT-guided fine needle aspiration cytology (FNAC) increases the accessibility of intra-abdominal masses to the liver and gall bladder with the advantages of low cost and high diagnostic yield. Cell block technique has been known for further increasing the diagnostic accuracy. We aimed to study the effectiveness of FNAC and the cell block method in cytological diagnosis of liver and gall bladder masses. We also followed a step-wise approach to increase the success rate. A 2-year observational study was done from July 2020 to June 2022. Total 80 guided (CT and ultrasound) aspirations were done from space occupying/mass lesions in the liver [74 (92.5%)] and gall bladder [6 (7.5%)], out of which cell blocks by the plasma thrombin method were prepared in 12 cases (15%). The on-site radiological details were noted, and rapid on-site evaluation was done in 65 cases (81.25%). The prepared cytology slides were stained with Papanicolaou, H and E and May-Grunwald Giemsa (MGG) stain. The cytological diagnosis was noted, and the uses and limitations (if any) were observed in each case. A step-wise structured questionnaire format was developed to assist the reporting pathologist so as not to miss out on important diagnostic observations, if present. FNAC in 71 cases (88.7%) gave a conclusive diagnosis. The maximum number of cases were of adenocarcinoma [38 (51.3%)] from the liver followed by hepatocellular carcinoma in 10 cases (13.5%). In gall bladder masses, all 6 cases (100%) were positive for malignancy, out of which 4 cases (66.7%) could be characterized as adenocarcinoma. The cell block preparation was helpful in reaching the diagnosis as well as typing the malignancy in 10 cases (83.3%). The chief limitation observed on conventional cytology smears was inadequate cellularity, which caused inconclusive diagnosis in 9 cases (11.25%). The reporting questionnaire was helpful chiefly in terms of time-efficient reporting in 34 cases (42.5%), increasing the ease and confidence in 69 cases (86.25%) and the advantage of reproducibility of data in all cases (100%) according to the case-by-case evaluation by the reporting pathologists. Guided FNAC in conjunction with the cell block technique is extremely helpful in the evaluation of mass lesions of the liver and gall bladder for cytological diagnosis. A proper step-wise approach may be useful to reach a quick and effective diagnosis.

Diagnostic Utility of Cell block and Immunocytochemistry in Differentiating Malignant from Non-malignant Effusions: A Cross-sectional Study

Introduction: Cytological evaluation of body cavity fluids has been widely employed in diagnosing the underlying aetiology. Differentiating reactive mesothelial cell proliferations from metastatic malignant cells based on cytomorphology alone is challenging. Therefore, the use of cell blocks in conjunction with immunocytochemistry can significantly improve diagnostic accuracy. Aim: To investigate the role of cell blocks and immunocytochemistry in distinguishing malignant from non- malignant effusion fluids. Materials and Methods: A prospective cross-sectional study was conducted on 70 serous effusion fluid samples (ascitic and pleural fluids) received in the Cytology section of the Pathology Department from October 2021 to November 2022. Relevant clinical details, including demographic information, age, gender, presenting complaints, and radiological and laboratory investigations, were documented from the patients’ medical records. All fluids underwent conventional cytology, and the remaining fluid was used for cell block preparations. Immunocytochemistry was performed using Ber-EP4 and Calretinin immuno-markers to differentiate between reactive mesothelial cells and malignant cells. The association between cytosmear/cell block and immunocytochemistry was calculated using the chi-square test. Results: Out of the 70 cases, 44 were pleural fluids, and 26 were ascitic fluids. Conventional cytology identified 11 positive cases, 20 suspicious cases, and 39 negative cases for malignancy. However, after cell block examination, the total number of positive cases reduced to 9, suspicious cases decreased to 12, and negative cases increased to 49, resulting in a 14.3% increase in diagnostic accuracy. Immunocytochemistry using Ber-EP4 showed strong positivity in 12 cases, indicating epithelial malignancy (adenocarcinoma), while 9 cases were Ber-EP4 negative. Calretinin positivity was observed in the mesothelial cells of all 21 cases where immunohistochemistry was performed, resulting in a 17.5% increase in diagnostic accuracy. Conclusion: The combination of cell block technique with conventional cytology improves the diagnostic yield and accuracy by providing better interpretation of architectural patterns and cytomorphology. Additionally, the application of immunocytochemistry using Ber-EP4 and Calretinin aids in distinguishing malignant from non-malignant serous effusions.