Comparison of Conventional Smear and Liquid-based Cytology Preparation in Diagnosis of Lung Cancer by Bronchial Wash and Transbronchial Needle Aspiration

Clinical values of different specimen preparation methods for the diagnosis of lung cancer by EBUS-TBNA

BACKGROUND AND OBJECTIVE

EBUS-TBNA has emerged as an important minimally invasive procedure for the diagnosis and staging of lung cancer. Our objective was to evaluate the effect of different specimen preparation from aspirates on the diagnosis of lung cancer.

METHODS

181 consecutive patients with known or suspected lung cancer accompanied by hilar / mediastinal lymphadenopathy underwent EBUS-TBNA from January 2019 to December 2022. Specimens obtained by EBUS-TBNA were processed by three methods: Traditional smear cytology of aspirates (TSC), liquid-based cytology of aspirates (LBC) and histopathology of core biopsies.

RESULTS

EBUS-TBNA was performed in 181 patients on 213 lymph nodes, the total positive rate of the combination of three specimen preparation methods was 80.7%. The diagnostic positive rate of histopathology was 72.3%, TSC was 68.1%, and LBC was 65.3%, no significant differences was observed (p = 0.29); however, statistically significant difference was noted between the combination of three preparation methods and any single specimen preparation methods (p = 0.002). The diagnostic sensitivity of histopathology combined with TSC and histopathology combined with LBC were 96.5 and 94.8%, the specificity was 95.0% and 97.5%, the PPV was 98.8% and 99.4%, the NPV was 86.4% and 81.2%, the diagnostic accuracy was 96.2% and 95.3%, respectively; The sensitivity and accuracy of above methods were higher than that of single specimen preparation, but lower than that of combination of three preparation methods.

CONCLUSION

When EBUS-TBNA is used for the diagnosis and staging of lung cancer, histopathology combined with TSC can achieve enough diagnostic efficiency and better cost-effectiveness.

Pitfalls in Respiratory Tract Cytopathology

BACKGROUND

Cytopathology is integral to the investigation and diagnosis of respiratory disease, and, in the last decade or so, transbronchial needle aspiration by endobronchial ultrasound has made possible diagnosis and staging of malignant thoracic tumours at a single procedure. In addition, interventional teams increasingly include cytopathologists and cytotechnologists who, by providing rapid onsite evaluation, ensure efficient sampling of intrathoracic targets with the ultimate goal of accurate diagnosis as well as sufficient material for comprehensive predictive testing. Nonetheless, "traditional" cytological investigations such as bronchial washings, brushings, and lavages are still carried out for investigation of both suspected neoplastic and non-neoplastic conditions, and all these procedures still produce specimens in which florid benign cells mimic malignancy, while truly neoplastic cells lurk quietly in the background. Furthermore, even when neoplasia is not suspected, issues in preparation and interpretation may render a final assessment inaccurate and, therefore, clinically unhelpful or misleading. In this overview, we have tried to adopt a format partly modelled on the passage of a specimen from clinical acquisition to laboratory endpoint, thus taking in potential pitfalls in communication, clinical interaction, transport, and clinic-based preparation, as well as in morphology, immunocytochemistry, and suitability for predictive testing. It is not exhaustive but highlights areas that may frequently be encountered or are part of our personal experience.

SUMMARY

The account highlights potential pitfalls in respiratory cytopathology at key stages of the process from acquisition to reporting and presents these in both flow diagram and tabular form. We hope this is useful for the increasingly collaborative roles of cytotechnologist and cytopathologist and their wider involvement in the clinical investigative teams.

KEY MESSAGES

Correct clinical and radiological information is crucially important and promotes the correct acquisition and processing of cytopathological specimens. Cross-discipline collaborative working ensures the most efficient use of the specimen such that diagnoses and predictive tests are performed on optimal material, reducing the potential for misinterpretation. Nonetheless, even with optimal material, morphological mimics and atypical antigen expression may mislead and render accurate diagnosis challenging.

Evaluating the comprehensive diagnosis efficiency of lung cancer, including measurement of SHOX2 and RASSF1A gene methylation

Methylation of the promoters of SHOX2 and RASSF1A (LungMe®) exhibits promise as a potential molecular biomarker for diagnosing lung cancer. This study sought to assess the aberrant methylation of SHOX2 and RASSF1A in broncho-exfoliated cells (BEC) and compare it with conventional cytology, histology examination, immunohistochemistry, and serum tumor markers to evaluate the overall diagnostic efficiency for lung cancer. This study recruited 240 patients, including 185 malignant cases and 55 benign cases. In our observation, we noted a slight reduction in the detection sensitivity, however, the ΔCt method exhibited a significant enhancement in specificity when compared to Ct judgment. Consequently, the ΔCt method proves to be a more appropriate approach for interpreting methylation results. The diagnostic sensitivity of cytology and histology was in ranged from 20.0%-35.1% and 42.9%-80%, respectively, while the positive detection rate of LungMe® methylation ranged from 70.0% to 100%. Additionally, our findings indicate a higher prevalence of SHOX2( +) among patients exhibiting medium and high expression of Ki67 (P < 0.01), as opposed to those with low expression of Ki67, but RASSF1A methylation did not show this phenomenon (P = 0.35). Furthermore, CEA, SCCA, and CYFRA21-1 showed positive detection rates of 48.8%, 26.2%, and 55.8%, respectively. Finally, we present a comprehensive lung cancer diagnostic work-up, including LumgMe® methylation. The combined analysis of SHOX2 and RASSF1A methylation serves as a powerful complement and extension to conventional methods, enhancing the accuracy of a lung cancer diagnosis with satisfactory sensitivity and specificity.

Endobronchial ultrasound-guided transbronchial needle aspiration for the diagnosis of pulmonary sarcoidosis: A 9-year experience at a single center

BACKGROUND

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is valuable for diagnosing pulmonary sarcoidosis. We aimed to evaluate the diagnostic yield of EBUS-TBNA and cytology in sarcoidosis during the first 9 years at our institution.

METHODS

Patients who underwent EBUS-TBNA for suspected sarcoidosis between January 2011 and November 2019 were identified retrospectively. EBUS-TBNA was performed with rapid on-site cytological evaluation of the samples. The final diagnosis was based on the pathology and/or cytology results, radiologic features, and clinical follow-up findings. The yield rate was analyzed annually.

RESULTS

Eighty patients underwent 83 EBUS-TBNA procedures for suspected sarcoidosis. In total, 136 lymph nodes were sampled. The mean number of lymph node stations sampled was 2.0 ± 0.6; the mean number of needle passes per lymph node was 3.5 ± 0.8. Sixty-five patients were diagnosed with sarcoidosis, with a total of 68 procedures. Nonnecrotizing granulomatous inflammation was detected in the EBUS-TBNA samples from 49/68 procedures (yield rate: 72.1%). Of 19 patients with sarcoidosis who did not obtain a pathological diagnosis with EBUS-TBNA, epithelioid cells and/or multinuclear giant cells suggestive of granulomatous inflammation were detected in five. The sensitivity, specificity, positive predictive value, and negative predictive value (NPV) for pathological diagnosis of sarcoidosis using EBUS-TBNA were 72.1%, 100%, 100%, and 24.0%, respectively. On using cytology, the sensitivity and NPV increased to 79.4% and 26.3%, respectively. The yield rate did not increase until 2016.

CONCLUSION

EBUS-TBNA is useful for diagnosing sarcoidosis. Cytology resulted in an additional yield rate of 7.3%, which improved as the number of cases increased.

Liquid-based rapid onsite evaluation of endobronchial ultrasound cytologies

INTRODUCTION

Rapid onsite evaluation (ROSE) generally uses smears made at the site of the procedure ("smear-based ROSE"). It requires considerable time, generally 2 individuals, technical expertise, and it can be difficult to estimate material available for ancillary studies. We developed an alternative ROSE using liquid-based cytology ThinPrep with hematoxylin and eosin (H&E) stain ("liquid-based ROSE") and assessed its advantages.

MATERIALS AND METHODS

Clinicians rinse the sample(s) into CytoRich Red and send to Pathology. A defined proportion of the needle rinse is removed for a ThinPrep stained with a rapid H&E. Adequacy and diagnosis were compared to final outcome. Total time was recorded.

RESULTS

Among 52 liquid-based ROSE readings, 28 (53.8%) were interpreted as "adequate" with final as adequate; 17 (32.7%) were interpreted as "inadequate" with final as inadequate; 7 (13.5%) were interpreted as "inadequate" with final as adequate. Of 23 readings provided with onsite diagnosis, 15 (65.2%) were interpreted as definitive positive or negative diagnoses; 6 (26%) were interpreted as nondiagnostic; and 2 (8.7%) were interpreted as atypical. All definitive diagnoses were concordant with final diagnoses. The time for liquid ROSE performance ranges from 6 to 22 minutes (mean: 13 minutes) and required only 1 individual.

CONCLUSIONS

Liquid-based ROSE allows accurate adequacy determination and diagnosis, takes about 15 minutes of cytologist time, and can be performed by just 1 person. The technique produces well-preserved and stained slides, it may allow a better estimation of the total amount of material in the specimen vial and may provide a better platform for telecytology.

Technical aspects of the use of cytopathological specimens for diagnosis and predictive testing in malignant epithelial neoplasms of the lung

Lung cancer is a leading cause of cancer mortality worldwide but recent years have seen a rapidly rising proportion of cases of advanced non-small cell carcinoma amenable to increasingly targeted therapy, initially based on the differential response to systemic treatment of tumours of squamous or glandular differentiation. In two-thirds of the cases, where patients present with advanced disease, both primary pathological diagnosis and biomarker testing is based on small biopsies and cytopathological specimens. The framework of this article is an overview of the technical aspect of each stage of the specimen pathway with emphasis on maximising potential for success when using small cytology samples. It brings together the current literature addressing pre-analytical and analytical aspects of specimen acquisition, performing rapid onsite evaluation, and undertaking diagnostic and predictive testing using immunocytochemistry and molecular platforms. The advantages and drawbacks of performing analysis on cell block and non-cell block specimen preparations is discussed.

Optimization of Sample Preparation Using Glass Slides for Spectral Pathology

The clinical translation of Fourier transform infrared (FT-IR) microspectroscopy in pathology will require bringing this technique as close as possible to standard practice in pathology departments. An important step is sample preparation for both FT-IR microspectroscopy and pathology. This should entail minimal disruption of standard clinical practice while achieving good quality FT-IR spectral data. In fact, the recently described possibility of obtaining FT-IR spectra of cells placed on glass substrates brings FT-IR microspectroscopy closer to a clinical application. We have now furthered this work in order to identify two different types of lung cancer cells placed on glass coverslips. Two types of sample preparation which are widely used in pathology, cytospin and smear, have been used. Samples were fixed with either methanol, used in pathology, or formalin (4% paraformaldehyde) used widely in spectroscopy. Fixation with methanol (alcohol-based fixative) removed lipids from cells causing a decrease in intensity of the peaks at 2850 cm^-1 and 2920 cm^-1. Nevertheless, we show for the first time that using either type of sample preparation and fixation on thin glass coverslips allowed to differentiate between two different types of lung cancer cells using either the lipid region or the fingerprint region ranging from 1800 cm^-1 to 1350 cm^-1. We believe that formalin-fixed cytospin samples would be preferred to study cells on thin coverslips using FT-IR microspectroscopy. This work presents a clear indication for future advances in clinical assessment of samples within pathology units to gain a deeper understanding of cells/tissues under investigation.

Values of different specimen preparation methods for the diagnosis of lung cancer by endobronchial ultrasound guided transbronchial needle aspiration

Background

Endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) has been become an important procedure for the diagnosis and staging of lung cancer. Our research identified the effects of different pathological preparation on the diagnosis of lung cancer for specimens obtained by biopsy.

Methods

Patients were clinically considered if lung cancer was accompanied by mediastinal or hilar lymph node enlargement between March 2014 and November 2017. Specimens obtained by EBUS-TBNA were treated by three methods: traditional smear cytology, liquid-based cytology (LBC) and histopathology.

Results

Of a total of 154 puncture sites from 153 patients, the total positive rate of combination for the three pathological treatment types (histopathology, direct traditional smear, and LBC) was 77.3%. The diagnostic positive rate for histopathology was 68.6%, direct traditional smear was 65.6%, and LBC was 60.4%; there was no significant differences among the three single pathological treatment types (P = 0.29), but there was a statistically significant difference between the combination of three treatments and any single pathological treatment type (P = 0.01). The diagnostic sensitivities of histopathology combined with traditional smear and histopathology combined LBC were 94.4 and 92.8%, respectively, the specificities and PPVs were both 100%, and the diagnostic accuracies were 95.5 and 94.2%, respectively; the sensitivities, specificities and diagnostic accuracies above were all higher than those of single specimen treatment and lower than those of the three combined.

Conclusion

When EBUS-TBNA is used for the diagnosis and staging of lung cancer, the use of histopathological sections combined with direct cytological smear should be sufficient and is the most economical choice.

Processing and Reporting of Cytology Specimens from Mediastinal Lymph Nodes Collected using Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration: A State-of-the-Art Review

Endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) is presently the preferred modality for sampling mediastinal lymph nodes. There is an unmet need for standardization of processing and reporting of cytology specimens obtained by EBUS-TBNA. The manuscript is a state-of-the-art review on the technical aspects of processing and reporting of EBUS-TBNA specimens. A literature search was conducted using the PubMed database, and the available evidence was discussed among the authors. The evidence suggests that at least one air-dried and one alcohol-fixed slide should be prepared from each lymph node pass. The remaining material should be utilized for microbiological analysis (in saline) and cell block preparation (10% formalin or other solutions). Wherever available, rapid-onsite evaluation should be performed to assess the adequacy of the sample and guide the need for additional material. The lymph node aspirate should also be collected in Roswell Park Memorial Institute solution in cases where lymphoma is under consideration. The use of liquid-based cytology provides good quality specimens that are free from blood and air-drying artifacts and can be used wherever available. Sample adequacy and the diagnostic category should be furnished separately in the cytology report.

Lung Molecular Cytopathology: EGFR and Beyond

Lung cancer (LC) is the leading cause of cancer-related mortality. Unfortunately, most patients of LC present at the advanced stage of the disease with a poor prognosis and 1-year survival of less than 20%. At the advanced stage of the disease, surgical resection cannot be possible, hence small biopsy or cytology specimens remain a choice for their correct diagnosis. The recognition of molecular drivers has revolutionized the treatment paradigm of non-small cell lung cancer (NSCLC) with introduction of tyrosine kinase inhibitors. Epidermal growth factor receptor (EGFR) gene mutations were identified, first, to be targeted in NSCLC followed by activating fusions in anaplastic lymphoma kinase (ALK) and rearrangements in c-ros oncogene 1 (ROS1) genes. In addition, the encouraging progress of immunotherapy in patients with NSCLC has been associated with predictive biomarker testing in the form of programmed death ligand-1 (PD-L1) immunohistochemistry assay. To test for these alterations, accurate biomarker testing is needed from biopsy or cytology specimens. In this brief review, testing of biomarkers is discussed using cytology specimens.

Tru-cut/core Biopsy versus FNAC: Pulmonary Tumors

Primary lung epithelial malignancies are the most common neoplasms among all pulmonary tumors. Lung cancer (LC) is the leading cause of cancer-related mortality for which a histologic or cytologic confirmation of malignancy is required before treatment. Specimen management is an important task for pathologists in the field of LC. Biopsy and fine needle aspiration are comparable. It is desirable to have both for diagnosis and mutation testing to maximize their use for patient care.