A combination of smears and cell block preparations provides high diagnostic accuracy for endobronchial ultrasound-guided transbronchial needle aspiration

Acquisition and Handling of Endobronchial Ultrasound Transbronchial Needle Samples: An American College of Chest Physicians Clinical Practice Guideline

BACKGROUND

Endobronchial ultrasound-guided transbronchial aspiration (EBUS-TBNA) has become the standard for initial lung cancer diagnosis and staging. Previous guidelines have generally focused on the "when" and "how" of EBUS-TBNA; however, little guidance is available on handling and processing specimens during and after acquisition to help optimize both diagnostic yield and tissue integrity for ancillary studies. This document examines the available literature on EBUS-TBNA specimen processing and handling.

STUDY DESIGN AND METHODS

Rigorous methodology was applied to provide a trustworthy evidence-based guideline and expert panel report. Panelists developed key clinical questions utilizing the Population, Intervention, Comparator, and Outcome (PICO) format, addressing specific topics in EBUS-TBNA specimen processing. MEDLINE (via PubMed) and the Cochrane Library were systematically searched to identify relevant literature, supplemented by manual searches. References were screened for inclusion with document evaluation tools to assess the quality of included studies, extract meaningful data, and grade the level of evidence to support each recommendation or suggestion.

RESULTS

Our systematic review and critical analysis of the literature of the 9 PICO questions related to handling and processing EBUS-TBNA specimens resulted in 9 evidence-based statements.

INTERPRETATION

Evidence of the handling and processing of EBUS-TBNA specimens varies in strength but is satisfactory in some areas to guide clinicians in certain aspects of specimen handling. Additional research in many aspects of specimen handling and processing is needed to help improve our knowledge base.

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.

Diagnostic Yield and Safety of the 19-Gauge versus 22-Gauge Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration Needle in Subjects with Sarcoidosis (GUESS)

INTRODUCTION

Observational data suggest that the 19-gauge (G) needle for endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) offers a higher diagnostic yield than the 22-G needle in sarcoidosis. No randomized trial has compared the yield of the two needles.

METHODS

We randomized consecutive subjects with suspected sarcoidosis and enlarged thoracic lymph nodes to undergo EBUS-TBNA with either the 19-G or the 22-G needle. We compared the study groups for diagnostic sensitivity (primary outcome) assessed by the yield of granulomas in subjects finally diagnosed with sarcoidosis. We also compared the sample adequacy, difficulty performing the needle puncture assessed on a visual analog scale (VAS), the subject's cough intensity on an operator-rated VAS, and procedure-related complications (secondary outcomes).

RESULTS

We randomized 150 (mean age, 43.0 years; 55% women) subjects and diagnosed sarcoidosis in 116 subjects. The diagnostic sensitivity of the 19-G needle (45/60, 75.0%) was not higher (p = 0.52) than the 22-G needle (39/56, 69.6%). We obtained adequate aspirates in 90.0% and 85.7% of subjects in the respective groups (p = 0.48). The operators had greater difficulty puncturing lymph nodes with the 19-G needle (p = 0.03), while the operator-assessed cough intensity was similar in the groups (p = 0.41). Transient hypoxemia was the only complication encountered during EBUS-TBNA (two subjects in either group).

CONCLUSION

We did not find the 19-G needle superior to the 22-G in diagnostic sensitivity, specimen adequacy, or safety of EBUS-TBNA in sarcoidosis. Puncturing the lymph nodes was more difficult with the 19-G needle.

The Contribution of Cell Blocks in the Diagnosis of Mediastinal and Hilar Lymphadenopathy Samples From Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration (EBUS-TBNA)

Background Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a diagnostic procedure that allows clinicians to stage lung cancer by sampling lymph nodes in the mediastinum. EBUS-TBNA is recommended as a first step prior to mediastinoscopy for lung cancer mediastinal staging. This procedure has greatly aided pulmonologists in diagnosing mediastinal pathologies with substantial progress. In this study, our aim is to analyze how cell blocks affect the diagnostic yield of mediastinal and hilar lymphadenopathy using an EBUS cytology needle. Methods This retrospective study was conducted at King Abdulaziz University Hospital between May 2021 and September 2021. Patients with mediastinal and hilar lymphadenopathy in the absence of known or suspected primary lung cancer were included. The EBUS procedure was performed using a flexible bronchoscope equipped with a working channel suitable for transbronchial needle aspiration under direct ultrasound guidance. Data were recorded using Microsoft Excel and analyzed using Statistical Package for the Social Sciences (SPSS) v. 26.0 (IBM Corp., Armonk, NY). Diagnostic accuracy measures were determined, and a p-value of 0.05 was established as the final threshold for statistical significance. Results The total number of patients in our study was 151. The sensitivity for cytology specimens, histology specimens, and a combined evaluation for the full group of patients was 77.14%, 83.33%, and 87.5%, respectively, with a negative predictive value of 27.22%, 25%, and 21.42%. The diagnostic accuracy for cytology specimens, histology specimens, and a combined evaluation was 71.42%, 76.19%, and 80%, respectively. Conclusion Our study found that the combined examination of specimens for both cytology and histology in the diagnosis of lung cancer, sarcoidosis, and tuberculosis resulted in a higher diagnostic yield compared to cytological assessment alone using EBUS-TBNA.

The Value and Limitations of Cell Blocks in Endobronchial Ultrasound-Guided Fine-Needle Aspiration Cytology: Experience of a Tertiary Care Center in North India

Background:

Endobronchial ultrasound (EBUS)-guided fine-needle aspiration cytology (FNAC) is recommended for diagnosing bronchial neoplasms and evaluating mediastinal lymph nodes. However, it may not be possible to subtype or definitely categorize many bronchial neoplasms on FNAC smears alone. Obtaining adequate diagnostic material is often a problem. In such cases, cell blocks made from FNAC material may serve as a useful adjunct. Aim: To study the value and limitations of cell blocks in adding diagnostic information to EBUS guided FNAC smears.

Material and Methods:

One hundred and eighty-five cases of EBUS guided FNAC having concomitant cell blocks were reviewed. The cases were evaluated for the extent of adequacy, of definite benign/malignant categorization and of definite subtyping in malignant tumors in these cases. The proportion of cases in which cell blocks added information to FNAC smears alone for the above parameters were calculated.

Results:

Cell blocks provided additional information in 31 out of 185 cases. Cell blocks were necessary for subtyping 24/59 malignant tumors, definite categorization into benign and malignant in 10/140 adequate samples, and increasing adequacy in 6/185 total samples. A total of 45 samples were inadequate in spite of adding information from cell blocks to smears.

Conclusion:

Cell blocks added clinically significant information to EBUS guided FNAC and should be used routinely. To make it more useful, alternative methods of cell block preparation (including proprietary methods) may be evaluated.

Role of Endobronchial Ultrasound Guided Transbronchial Needle Aspiration with Cellblocks in Diagnosis and Subtyping of Intrathoracic Lesions: Two Year Experience from a Tertiary Care Center

Background

Endobronchial ultrasound guided transbronchial needle aspiration (EBUS-TBNA) allows precise real-time sampling of intrathoracic lesions and is a minimally invasive, safe, and cost effective technique with high diagnostic yield. The aim of the current study is to evaluate utility of EBUS-TBNA cytology with cellblocks (CBs) in the diagnosis and subtyping of the intrathoracic lesions.

Materials and Methods

It was a prospective study conducted from October 2015 to October 2017. We received 233 cases of intrathoracic lesions for EBUS-TBNA, of which CB was made in 217 cases. A flexible endobronchial ultrasound scope was used to sample the lesions.

Results

There were 89 females and 128 males amongst the total 217 patients (age range: 14-85 years, mean age: 48.35 years). The smears from EBUS-TBNA contained adequate material in 137/144 [95.1%] non-neoplastic cases and 34/36 [94.4%] of the neoplastic cases, whereas the CBs provided adequate material in 94/144 [65.3%] non-neoplastic cases and 37/40 [92.5%] neoplastic cases. The CB helped subtyping the malignancy in 19 cases and of these immunohistochemistry (IHC) was done on the CB in 15 cases. The biopsy was non-diagnostic in 17/36 cases of granulomatous pathology and 4/18 neoplastic cases diagnosed with EBUS-TBNA.3.

Conclusions

EBUS-TBNA provides rapid diagnosis through cytology and the material recovered in the same setting for the CB preparation can be used for immunohistochemical analysis and it may at times provide the diagnosis in cases where the smears are non-diagnostic.

Comparison of endobronchial ultrasound-guided transbronchial needle aspiration cytology versus cell blocks in adults with undiagnosed mediastinal lymphadenopathy

Introduction

Retrospective studies have shown improved diagnostic yield of combined cytology and cell blocks specimens from endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) with variable additional yields in cell blocks. In this prospective study, we assessed the diagnostic performance of cytology and cell blocks in patients undergoing EBUS-TBNA.

Methods

This was a single-center, cross-sectional study conducted between December 2017 and November 2019 including patients aged ≥18 years with mediastinal lymphadenopathy. EBUS-TBNA was performed under conscious sedation using 22G needles. Both cytology smears and cell blocks by the tissue coagulum clot technique were prepared for each patient without rapid on-site evaluation.

Results

Data were analyzed for 93 patients (mean age 54.25 ± 13.7 years, 73 males) where both cytology and cell blocks were available. Sample adequacy was 100%. Overall diagnostic yield either by cytology or cell block was 83%. Cytology yield was 79.6%, whereas cell block was diagnostic in 73% of patients (P < 0.001). The overall additional yield of cell blocks was 3.2%. Cell blocks had additional yields of 1.8%, 0%, and 14.3% in malignancy, tuberculosis, and sarcoidosis, respectively. Tumor histology was better identified in 76% of positive cell blocks, and accurate histological subtyping was possible in 32.6% cases. Immunohistochemistry was feasible in 82.5% of all positive cell blocks, and these were judged to be adequate for the mutational analysis.

Conclusions

Compared to cytology, EBUS-TBNA cell blocks did not significantly increase the overall diagnostic yield in unselected patients. However, cell blocks are beneficial in the characterization of tumor morphology and histological subtyping of lung cancer.

Subtyping and EGFR mutation testing from blocks of cytological materials, based on liquid-based cytology for lung cancer at bronchoscopic examinations

BACKGROUND

Liquid-based cytology (LBC) allows immunohistochemistry (IHC), fluorescence in situ hybridization, and molecular testing to be performed in fixed cell materials. We examined the feasibility of subtyping and EGFR mutation testing of bronchoscopic samples from patients with lung cancer using cell blocks (CB) based on LBC fixation (LBC-CB).

METHODS

We included 35 consecutive patients with peripheral lung nodules who underwent endobronchial ultrasonography with a guide sheath in our hospital. Thirty of these patients were diagnosed with lung cancer by obtaining cytological samples. Cytological subtyping was performed with IHC using LBC-CB, and the Cobas EGFR Mutation Test ver. 2 was performed using extracted genomic DNA from the LBC-CB, formalin-fixed paraffin-embedded (FFPE) tissue, and matched plasma.

RESULTS

Of the 30 cases, 25 were classified cytomorphologically as adenocarcinoma (ADC, n = 17) and squamous-cell carcinoma (SQCC, n = 8). The remaining five cases were classified by IHC as favor ADC (n = 3) and favor SQCC (n = 2) according to the WHO criteria. In the final ADC group (n = 20), EGFR mutations on the LBC-CB were identified in eight cases (40%; 1 exon 19 deletion, 6 L858R, and 1 L861Q). Mutations in FFPE samples were identified in seven cases (35%) at the same site in each case. Plasma EGFR mutations were identified in four cases (20%) at the same site. The CB detection rate was higher than for FFPE and plasma.

CONCLUSION

LBC-CB is suitable for subtyping and EGFR mutation testing in lung cancers.

Cytology and the cell block method in diagnostic characterization of canine lymphadenopathy and in the immunophenotyping of nodal lymphoma

Minimally invasive techniques used to evaluate canine peripheral lymphadenopathy (PLN), including fine needle aspiration biopsy with cytological evaluation (FNAB-C) and flow cytometry (FC), have benefits and limitations. The cell block (CB) method is an alternate processing technique in which fine needle aspirate biopsy samples are concentrated, fixed, and embedded in paraffin for routine histological processing/staining. Utilizing three observers, we determined the diagnostic value of the CB in evaluating canine PLN across six categories (non-diagnostic, reactive, inflammatory/infectious, probable lymphoma and lymphoma, metastatic neoplasia) and correlated findings to immunophenotypic and clonal antigen receptor rearrangement results in canine nodal lymphoma. Eighty-five paired FNAB-C and CB samples were evaluated from canine patients presenting to the University of Minnesota Veterinary Oncology or Internal Medicine services. Diagnostic quality samples were obtained in 55/85 (65%) CB and 81/85 (95%) FNAB-C samples, respectively, and nodal pathology impacted CB diagnostic yield. Overall percent agreement between diagnostic-quality FNAB-C and CB samples was 86%, but increased to 95% if the categories of lymphoma and probable lymphoma were combined. There was 100% agreement for both the diagnoses of metastatic neoplasia and reactive lymph nodes and 92% agreement for the diagnosis of lymphoma/probable lymphoma. Using immunohistochemistry (IHC), CB samples correctly immunophenotyped 22/23 (96%) cases of B-cell lymphoma, but only 1/6 (17%) cases of T-cell lymphoma. IHC was not completed on nine cases of lymphoproliferative disease because of insufficient cellularity. When the CB method (CBM) yielded diagnostic quality samples there was good to excellent agreement with FNAB-C samples and CB samples were suitable for some IHC tests.

Contribution of cell blocks obtained through endobronchial ultrasound-guided transbronchial needle aspiration for the determination of lung cancer subtypes

INTRODUCTION

It is crucial to diagnose the subtype of lung cancer quickly and accurately for effective therapy. Conventional cytology staining sometimes provides limited information, and additional tissue is often required to diagnose lung cancer. Cell blocks (CB) recovered during endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) increases the diagnostic accuracy of the procedure and the likelihood of additional valuable histochemical and immunohistochemical staining.

OBJECTIVES

To evaluate the diagnostic significance of smears and CBs for lung cancer subtypes METHODS: Records of patients who underwent EBUS-TBNA between July 2014 and December 2016 for lung cancer diagnosis and/or staging were retrospectively analysed.

RESULTS

The study included 156 patients and 232 LNs diagnosed as malignancies. Twenty-seven patients were diagnosed with small cell lung cancer (SCLC), and 129 were diagnosed with non-small cell lung carcinoma (NSCLC) (68 patients adenocarcinoma, 36 patients squamous cell carcinoma, 23 patients NSCLC if not otherwise stated, 1 patient large cell carcinoma and 1 patient pleomorphic carcinoma). The mean age was 60.5 ± 10.2 years, and 74.5% of the patients were males. The diagnostic rate for CBs was 231/232 (99.6%) and was 206/232 (88.8%) (P < .001) for smears. The diagnostic rate for SCLC was 37/39 (94.9%) for smears and 39/39 (100%) for CB (P < .001). For NSCLC, it was 169/193 (87.6%) for smears and 192/193 (99.5%) for CB (P < .001).

CONCLUSIONS

Cell-block preparation after an EBUS-TBNA is a simple method that provides important additional information related to lung cancer for morphological analyses.

Comparison of multiple techniques for endobronchial ultrasound-transbronchial needle aspiration specimen preparation in a single institution experience

BACKGROUND

The optimal method for specimen preparation of endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) is still controversial. This study aims to compare several techniques available for EBUS-TBNA specimen acquisition and processing, in order to identify the best performing technique.

METHODS

We retrospectively reviewed the data of 199 consecutive patients [male, 73%; median age, 64 years (IQR: 52-74 years)] undergoing EBUS-TBNA at our institution from 2012 through 2014 for diagnosis of hilar-mediastinal lymph node enlargement suspect of neoplastic (n=139) or granulomatous (n=60) disease. All procedures were performed by two experienced bronchoscopists, under conscious sedation and local anaesthesia, using 21/22-Gauge (G) needle, without rapid on-site evaluation (ROSE). Five specimen-processing techniques were used: cytology slides in 42 cases (21%); cell-block in 25 (13%); core-tissue in 60 (30%); combination of cytology slides and core-tissue in 51 (26%); combination of cytology slides and cell-block in 21 (10%). To assess the diagnostic accuracy of each tissue-processing technique we compared the EBUS-TBNA results to those obtained with surgical lymphadenectomy, or 1-year follow-up in non-operated patients.

RESULTS

Diagnostic yield, accuracy and area under the curve (AUC) were as follows. Cytology slides: 81%, 80%, 0.90; cell-block: 48%, 33%, 0.67; core-tissue: 87%, 99%, 0.96; cytology slides + core-tissue: 80%, 100%, 1.00; cytology slides + cell-block: 86%, 100%, 1.00. Cytology slides and core-tissue method showed non-significantly different diagnostic yield (P=0.435) and AUC (P=0.152).

CONCLUSIONS

In our single-institution experience, cytology slides and core-tissue preparations demonstrated high and similar diagnostic performance. Cytology slides combination with core-tissue or cell-block showed the highest performance, however these combination methods were more resource-consuming.

Contribution of cell block obtained by endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis of malignant diseases and sarcoidosis

AIM

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a safe and minimally invasive procedure that can be performed in outpatient settings. Several studies have demonstrated the usefulness of EBUS-TBNA in the diagnosis of sarcoidosis and malignant diseases. This study focused on the role of cell block (CB) analysis in determining the diagnostic yield of EBUS-TBNA in malignant diseases and sarcoidosis.

MATERIALS AND METHODS

The study was conducted at a training and research hospital. Records of patients who underwent EBUS-TBNA between March 2011 and December 2014 for diagnosed sarcoidosis or malignancy were retrospectively analyzed. Results of all EBUS-TBNA smears and CB were separately evaluated to determine the diagnostic value of each.

RESULTS

There were 84 sarcoidosis and 179 malignancy patients. In the malignancy group, CB contributed to cancer diagnosis in 15 (8.3%) patients and subclassification in 19 (10.6%) patients. In the sarcoidosis group, for 45.2% of patients (38/84), smears were not diagnostic but CB showed granulomatous inflammation.

CONCLUSION

CB significantly increases the diagnostic yield of EBUS-TBNA for sarcoidosis. In our study, in the malignancy group the diagnostic yield was low but it was helpful for subclassification, especially for adenocarcinoma.

Pre-analytical issues in effusion cytology

Effusions or body cavity fluids are amongst the most commonly submitted samples to the cytology laboratory. Knowledge of proper collection, storage, preservation and processing techniques is essential to ensure proper handling and successful analysis of the sample. This article describes how the effusions should be collected and proper conditions for submission. The different processing techniques to extract the cellular material and prepare slides satisfactory for microscopic evaluation are described such as direct smears, cytospins, liquid based preparations and cell blocks. The article further elaborates on handling the specimens for additional ancillary testing such as immunostaining and molecular tests, including predictive ones, as well as future research approaches.

Direct comparison of liquid-based and smear-based cytology with and without rapid on-site evaluation for fine needle aspirates of thoracic tumors

BACKGROUND

Liquid-based cytology (LBC) and rapid on-site evaluation (ROSE) are proposed to improve the quality of fine needle aspirates (FNA) and their diagnostic yield compared with conventional smear cytology (CSC). This prospective study directly compared outcomes of sonar-guided FNA of thoracic tumors supported by LBC, CSC, or CSC with ROSE.

METHODS

Three aspirates each for both LBC and CSC with separate 22G spinal needles in a randomized, alternating sequence during 64 transthoracic FNA of thoracic tumors were collected. Smears were prepared by cytology staff on site but evaluated with ROSE only when all six samples had been collected. If no diagnostic material was found on the first three CSC additional needle passes guided by ROSE were performed.

RESULTS

Final diagnoses were non-small cell lung cancer in 50 (78.1%), small cell lung cancer in 11 (17.2%), mesothelioma in 1 (1.6%), and inflammation in 2 cases (3.1%), respectively. LBC and CSC were diagnostic in 42 (65.6%) and 49 (76.6%) cases, respectively (P = 0.039), with both methods diagnostic in 41 cases (64.1%). Fifteen cases (23.4%) remained undiagnosed following three passes for CSC but 9 (14.1%) of these were diagnosed using FNA and ROSE with a total yield of 58 cases (90.6%; P < 0.001).

CONCLUSION

The diagnostic yield of transthoracic FNA submitted for LBC is significantly lower than with CSC when slides are prepared professionally. ROSE significantly increases the yield of transthoracic FNA.

Strategic management of transthoracic needle aspirates for histological subtyping and EGFR testing in patients with peripheral lung cancer: An institutional experience

BACKGROUND

Lung cancer therapy is personalized based on the histological subtype and molecular status. Totally, 70% of lung cancer patients present in advanced stages and are diagnosed on small biopsy or cytology specimens, hence an accurate but tissue-sparing approach is necessary. This study aimed to demonstrate efficient utilization of cell block (CB) on transthoracic needle aspiration (TTNA) for lung cancer subtyping, and to investigate the usefulness of needle washing after TTNA for assessing EGFR molecular status.

METHODS

Each TTNA specimen from the 79 peripheral lung masses was divided into three parts; liquid-based cytology (LBC), CB (with or without immunohistochemistry), and needle washing for analysis of EGFR mutation using peptide nucleic acid-mediated real-time PCR clamping.

RESULTS

Totally 79 specimens were diagnosed as malignancy, 75 (94.9%), benign, 3 (3.8%), and inadequate specimen, 1 (1.3%). The combination of LBC and CB (92.0%) showed a higher diagnostic yield for definitive subtyping of lung cancer than LBC alone (72.0%). Of the 75 malignant cases, 17 (22.7%) showed an EGFR mutation in needle washing specimens. EGFR mutational status was compared in all paired needle washing and scraped CBs with a 100% concordance.

CONCLUSIONS

We hereby proposed a strategy to maximize biological information retrieval from a limited TTNA specimen in patients with peripheral lung cancer. This algorithm indicated CB preparation for accurate histological subtyping and waste needle washing for molecular testing.

Guideline for the acquisition and preparation of conventional and endobronchial ultrasound-guided transbronchial needle aspiration specimens for the diagnosis and molecular testing of patients with known or suspected lung cancer

RATIONALE

Conventional transbronchial needle aspiration (TBNA) and endobronchial ultrasound (EBUS)-TBNA are widely accepted tools for the diagnosis and staging of lung cancer and the initial procedure of choice for staging. Obtaining adequate specimens is key to provide a specific histologic and molecular diagnosis of lung cancer.

OBJECTIVES

To develop practice guidelines on the acquisition and preparation of conventional TBNA and EBUS-TBNA specimens for the diagnosis and molecular testing of (suspected) lung cancer. We hope to improve the global unification of procedure standards, maximize the yield and identify areas for research.

METHODS

Systematic electronic database searches were conducted to identify relevant studies for inclusion in the guideline [PubMed and the Cochrane Library (including the Cochrane Database of Systematic Reviews)].

MAIN RESULTS

The number of needle aspirations with both conventional TBNA and EBUS-TBNA was found to impact the diagnostic yield, with at least 3 passes needed for optimal performance. Neither needle gauge nor the use of miniforceps, the use of suction or the type of sedation/anesthesia has been found to improve the diagnostic yield for lung cancer. The use of rapid on-site cytology examination does not increase the diagnostic yield. Molecular analysis (i.e. EGFR, KRAS and ALK) can be routinely performed on the majority of cytological samples obtained by EBUS-TBNA and conventional TBNA. There does not appear to be a superior method for specimen preparation (i.e. slide staining, cell blocks or core tissue). It is likely that optimal specimen preparation may vary between institutions depending on the expertise of pathology colleagues.

Cell blocks in cytopathology: a review of preparative methods, utility in diagnosis and role in ancillary studies

The cell block (CB) is a routine procedure in cytopathology that has gained importance because of its pivotal role in diagnosis and ancillary studies. There is no precise review in the published literature that deals with the various methods of preparation of CB, its utility in diagnosis, immunocytochemistry (ICC) or molecular testing, and its drawbacks. An extensive literature search on CB in cytology using internet search engines was performed for this review employing the following keywords: cell block, cytoblock, cytology, cytopathology, methods, preparation, fixatives, diagnostic yield, ancillary and molecular studies. Ever since its introduction more than a century ago, the CB technique has undergone numerous modifications to improve the quality of the procedure; however, the overall principle remains the same in each method. CBs can be prepared from virtually all varieties of cytological samples. In today's era of personalized medicine, cytological specimens, including CBs, augment the utility of cytological samples in analysing the molecular alterations as effectively as surgical biopsies or resection specimens. With the availability of molecular targeted therapy for many cancers, a large number of recent studies have used cytological material or CBs for molecular characterization. The various techniques of CB preparation with different fixatives, their advantages and limitations, and issues of diagnostic yield are discussed in this review.

The contribution of cell blocks in the diagnosis of mediastinal masses and hilar adenopathy samples from echobronchoscopy

BACKGROUND

Cell block material from puncture can be obtained with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in many cases. The aim of this study was to analyse the value of additional information from cell blocks obtained with EBUS-TBNA samples from mediastinal and hilar lymph nodes and masses.

METHODS

Review of pathology reports with a specific diagnosis obtained from EBUS-TBNA samples of mediastinal or hilar lesions, prospectively obtained over a two-year period. The generation of cell blocks from cytology needle samples, the contribution to morphological diagnosis, and the possible use of samples for immunohistochemistry were analysed.

RESULTS

One hundred and twenty-nine samples corresponding to 110 patients were reviewed. The diagnosis was lung cancer in 81% of cases, extrapulmonary carcinoma in 10%, sarcoidosis in 4%, lymphoma in 2.7%, and tuberculosis in 0.9%. Cell blocks could be obtained in 72% of cases. Immunohistochemistry studies on the cell blocks were significantly easier to perform than on conventional smears (52.6% vs. 14%, P<.0001). In 4cases, the cell block provided an exclusive morphological diagnosis (3sarcoidosis and one metastasis from prostatic carcinoma) and in 3carcinomas, subtype and origin could be identified. Exclusive diagnoses from the cell block were significantly more frequent in benign disease than in malignant disease (25% vs 0.9%, P=.002).

CONCLUSIONS

Cell blocks were obtained from 72% of EBUS-TBNA diagnostic procedures. The main contributions of cell blocks to pathology examinations were the possibility of carrying out immunohistochemical staining for the better classification of neoplasms, especially extrapulmonary metastatic tumours, and the improved diagnosis of benign lesions.

The implementation of liquid-based cytology for lung and pleural-based diseases

OBJECTIVE

First introduced for the processing of cervico-vaginal samples, liquid-based cytology (LBC) soon found application in nongynecological specimens, including bronchoscopic brushings, washings and transcutaneous and transbronchial aspiration biopsy of the lung as well as pleural effusions. This article reviews the existing literature related to these specimens along with the authors' own experience.

STUDY DESIGN

A literature review was conducted through Ovid MEDLINE and PubMed search engines using several key words.

RESULTS

Most of the literature is based on data collected through the use of split samples. The data confirms that the use of LBC is an acceptable, and sometimes superior, alternative to the conventional preparations (CP). LBC offers several advantages, including the ability to transport in a stable collecting media, elimination of obscuring elements, ease of screening, excellent preservation, random representative sample, and application of ancillary techniques on additional preparations. Some diagnostic pitfalls related to the introduced artifacts were reported.

CONCLUSION

The utilization of LBC offers many advantages over CP and has a diagnostic accuracy that is equal to or surpasses that of CP. LBC affords a bridge to the future application of molecular and other ancillary techniques to cytology. Knowledge of the morphological artifacts is useful at the early stages of implementation.

Improved efficacy of endobronchial ultrasound-guided fine-needle aspiration biopsy in comparison to endobronchial ultrasound-guided miniforceps biopsy

OBJECTIVE

Endobronchial ultrasound-guided fine-needle aspiration (EBUS-FNA) cytology and EBUS-miniforceps biopsy (MFB) have emerged as less invasive tools for evaluating mediastinal lymph nodes and pulmonary lesions. The aim of this study is to compare the diagnostic yields of EBUS-FNA cytology to EBUS-MFB.

STUDY DESIGN

A retrospective cohort study was performed by reviewing the database at our institution between December 12, 2010, and August 10, 2012. A total of 476 consecutive cases were identified. Of these, 227 patients had concurrent FNA and MFB taken during the procedure. The results and diagnostic yields of both techniques are calculated.

RESULTS

Of the 476 cases, the mean age was 62 ± 14 years with 53% being males. In 453 of the total cases, the less invasive FNA technique alone produced enough diagnostic cytology material negating the need for concurrent MFB. Of these FNA cases, 280 were diagnosed as malignant neoplasms. The diagnostic yield of EBUS-FNA cytology was comparable to EBUS-MFB (95% FNA and 94% MFB). There were discordant diagnoses between cytology and histology in 19 of the 227 (∼8.4%) cases.

CONCLUSIONS

EBUS-FNA cytology is a more efficacious diagnostic modality compared to EBUS-MFB.