Role of endobronchial needle aspiration during bronchoscopy in exophytic endobronchial lesions: A single-center experience of 810 cases in tertiary care setting

Shital Patil; Gajanan Gondhali; Shubhangi Khule; Deepak Patil

doi:10.4103/aort.aort_33_22

ORIGINAL ARTICLE

Year : 2023 | Volume : 3 | Issue : 1 | Page : 35-42

Role of endobronchial needle aspiration during bronchoscopy in exophytic endobronchial lesions: A single-center experience of 810 cases in tertiary care setting

Shital Patil¹, Gajanan Gondhali², Shubhangi Khule³, Deepak Patil²
¹ Department of Pulmonary Medicine, MIMSR Medical College, Latur, Maharashtra, India
² Department of Internal Medicine, MIMSR Medical College, Latur, Maharashtra, India
³ Department of Pathology, MIMSR Medical College, Latur, Maharashtra, India

Date of Submission	05-Dec-2022
Date of Decision	14-Dec-2022
Date of Acceptance	15-Dec-2022
Date of Web Publication	16-May-2023

Correspondence Address:
Dr. Shital Patil
Department of Pulmonary Medicine, MIMSR Medical College, Latur, Maharashtra
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/aort.aort_33_22

Abstract

INTRODUCTION: Globally, lung cancer is the leading cause of new cancer diagnosis and deaths. Despite advancement in diagnostic modalities lung cancer diagnosis is often delayed due to a lack of bronchoscopy facilities and techniques. In the present study, we have analyzed the role of bronchoscopy in the diagnosis of lung cancer with special emphasis on endobronchial needle aspiration (EBNA) cytology in comparison to other conventional diagnostic techniques (CDTs) such as bronchial wash (BW) and forcep biopsy (FB).
METHODS: Prospective, observational study screened 1280 cases with suspected lung malignancy on a clinical and radiological basis. Bronchoscopy-guided techniques such as EBNA, BW, and FB are used in exophytic endobronchial lesions (EELs) in confirming the diagnosis of lung cancer and to find additive yield over other techniques such as BW and FB. Rapid on-site evaluation analysis of all EBNA samples done in pathology laboratory allied center. Finally, histopathology proven 810 lung malignancy cases are included in this study. Statistical analysis is done using Chi-square test.
RESULTS: In the present study, 810 diagnosed lung cancer patients between 29 and 85 years of age group predominant males 59.25% (480/810) and smokers by addiction in 63.20% (512/810) cases. Presented with cough in 82.09% (665/810), clubbing in 56.17% (455/810) cases, and mass lesion in chest radiograph in 42.22% (342/810) cases. Anatomical location is documented on the right side of tracheobronchial in 59.01% (478/810) cases during bronchoscopy. The yield of FB and FB plus bronchial wash in EEL is 89.25% (723/810) and 93.08% (754/810), respectively. The yield of EBNA, EBNA plus bronchial wash, and EBNA plus FB in EEL is 64.56% (523/810), 67.28% (545/810), and 97.65% (791/810), respectively. Total yield of all fiberoptic bronchoscopy-guided procedures (EBNA + FB + BW) in EEL is 100%. Additional yield of EBNA in EEL over other CDTs is 6.92%. Sensitivity of FB and EBNA in diagnosing lung malignancy in EEL is 89.25% and 64.56%, respectively. FB is more sensitive technique than EBNA in EEL (P < 0.00001). Sensitivity of FB plus bronchial wash in EEL is 93.08% (754/810). Sensitivity of EBNA plus bronchial wash in EEL is 67.28% (545/810). Sensitivity of EBNA plus FB in EEL is 97.65% (791/810) (P < 0.00001).
CONCLUSIONS: EBNA has documented very crucial role in diagnosing lung cancer in comparison to other CDTs. Although FB is a more sensitive test than EBNA in EEL in diagnosing disease, we have documented EBNA has significant additive yield in proportionate number of cases. EBNA is safe, sensitive, and cytology samples can give comparable results to histopathology.

Keywords: Bronchial wash, bronchoscopy, cytology, endobronchial needle aspiration, forcep biopsy

How to cite this article:
Patil S, Gondhali G, Khule S, Patil D. Role of endobronchial needle aspiration during bronchoscopy in exophytic endobronchial lesions: A single-center experience of 810 cases in tertiary care setting. Ann Oncol Res Ther 2023;3:35-42

How to cite this URL:
Patil S, Gondhali G, Khule S, Patil D. Role of endobronchial needle aspiration during bronchoscopy in exophytic endobronchial lesions: A single-center experience of 810 cases in tertiary care setting. Ann Oncol Res Ther [serial online] 2023 [cited 2023 May 31];3:35-42. Available from: http://www.aort.info/text.asp?2023/3/1/35/376897

Introduction

Globally, lung cancer is the leading cause of new cancer diagnosis and deaths. Despite advancement in diagnostic modalities lung cancer diagnosis is often delayed due to a lack of bronchoscopy facility and techniques. In India, lung cancer accounts for 5.9% of all cancers and 8.1% of all cancer-related deaths.^[1] A history of bronchoscope use to examine tracheobronchial tree was traced to 18^th century and used rigid illuminating pipes.^[2] In mid-19^th century Ikeda invented fiberoptic bronchoscopy which has revolutionized the practice of interventional pulmonary medicine.^[3] Modifications and advancements in bronchoscopy have undergone in the past five decades such as autofluorescence techniques for early diagnosis of lung cancer, real-time image-guided sampling for the exact staging of lung cancer by mediastinal lymph.^[4] In addition, bronchoscopy advancement such as cryotherapy, argon plasma coagulation, laser, and electrocautery can be utilized now for the treatment of central airway lung cancers and maintaining patency of central airways.^[4]

The yield of various bronchoscopic techniques such as bronchial washing, bronchial brushing, and endobronchial and transbronchial biopsy depends on the visibility of tumors endoscopically. In endobronchial pathology, the yield of these techniques is satisfactory and highest for forcep biopsy (FB) 74% in comparison to bronchial brushing 59% and bronchial washing 48%. Significant increase in yield of bronchoscopy observed with combination of all these modalities up to 88%.^[4] Bronchoscopic lesions or abnormalities have been classified as endobronchial, submucosal, and peribronchial types according to their visibility. Needle aspiration cytology has been validated over decades during bronchoscopy for the diagnosis of lung cancer in all these three types of lesions and categorized as endobronchial needle aspiration (EBNA) cytology and transbronchial needle aspiration (TBNA) cytology.^[5] The addition of EBNA or TBNA in these lesions enhanced diagnostic yield and sensitivity of bronchoscopy procedure in addition with other conventional diagnostic modalities.^[5] TBNA is superior to all other conventional sampling modalities in peribronchial and submucosal lesions and its results are comparable with bronchoscopic FB in endobronchial tumor with an average diagnostic yield of 80%.^[6] Dasgupta et al.^[5] and Govert et al.^[6] documented use of EBNA along with other modalities during bronchoscopy in diagnosis of lung cancer in exophytic endobronchial lesions (EELs) and observed additive yield of EBNA and specifically mentioned EBNA is the only positive test in proportionate number of cases.

Bronchoscopy-guided EBNA/TBNA is complementary to other conventional diagnostic techniques (CDTs) such as bronchial wash, bronchial brush cytology, and FB.^[7],[8] Interestingly, conventional TBNA/EBNA is still underutilized in majority of bronchoscopy centers across the world.^[9] Reasons for underutilization of this novel technique EBNA/TBNA would be inadequate trainings to technique, difficulty in needle handling during bronchoscopy and cytology technique, decreased yield with poor technique and inadequate laboratory backup due to lack of rapid onsite evaluation (ROSE) facility, and finally lack of cytopathology expertise over histopathology in lung malignancy.^[10] Despite an increase in diagnostic yield by the addition of EBNA/TBNA to other conventional diagnostic modalities, it is not possible to perform all techniques in the same patient.^[10] In the present study, we have utilized all conventional fiberoptic bronchoscopy-guided diagnostic modalities including EBNA in diagnosing lung malignancies.

Methods

Data source

Prospective, observational study conducted from January 2013 to December 2021 in Respiratory Medicine and Critical Care Medicine Department in Venkatesh chest Hospital and MIMSR Medical College Latur. The objectives of the present study were to document the role of EBNA in EELs in confirming the diagnosis of lung cancer and to find out additive yield over other conventional techniques such as bronchial wash and FB. A total of 1280 suspected lung malignancies on a clinical and radiological basis were screened and finally, 810 confirmed lung cancer cases were included in the study after the hospital's ethical committee approval. We have taken written informed consent of all study patients [Figure 1].

Figure 1: The flow of the study. EBNA: Endobronchial needle aspiration cytology, BW: Bronchial wash, FB: Forcep biopsy

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Inclusion criteria

suspected lung malignancies on the clinical and radiological basis such as:

Cases with unexplained paralysis of vocal cord (hoarseness of voice) or stridor
Chest X-ray with radiological features of malignancy (coin lesions, mass lesions, mediastinal widening, unilateral high hemidiaphragm, segmental/complete lung collapse, and nonresolving pneumonia)
Normal chest X-ray with high clinical suspicion, localized monophonic wheeze, endobronchial disease or growth symptoms such as hemoptysis, persistent cough, cases with suspected recurrent postobstructive pneumonia, suspicious sputum cytology, unexplained and recurrent pleural effusion.

Exclusion criteria

Cases unfit for bronchoscopy were excluded such as:

Cases with coagulopathy which cannot be corrected and platelets
Cases with mechanical ventilation with high positive end-expiratory pressure
Cases with refractory hypoxemia
Cases with recent myocardial infarction or unstable angina
Cases with significant dysrhythmia and hemodynamic instability
Cases with poor ability to cooperate with procedure.

Ethical approval

This study is approved by the Ethics Committee of Venkatesh Chest Hospital and Critical Care Center and MIMSR Medical College, Latur, India (Approval # VCC/382013; Approval date October 6, 2013).

Bronchoscopic definition of exophytic endobronchial growth

During the bronchoscopy procedure, operators notified different types of endobronchial growth patterns. These EELs were described as “cauliflower-like, pedunculated, polypoidal, nodular exophytic, multinodular ulcerated” endobronchial growth [Figure 1].

Lesions with normal endobronchial mucosa with bulge (peribronchial growth) and abnormal endobronchial mucosa without oblivious growth were not included in the definition of endobronchial growth.

Bronchoscopy procedure in endoscopy suit

The bronchoscopy procedure was performed in endoscopy suit by Fujinon Epx 201H bronchoscope by two operators/teaching faculties of our institute trained in all bronchoscopy techniques including EBNA. The bronchoscopy procedure followed standard guidelines for topical analgesia during endoscopy used 10% lignocaine solution. The bronchoscope was introduced transnasally in majority of cases and few cases required oral introduction whenever difficulty in nasal negotiation in presence of nasal mucosa hypertrophy. Nasal analgesia with xylocaine jelly, and oropharyngeal mucosa with xylocaine spray and vocal cords and epiglottis with bronchoscopic instillation topical 10% xylocaine.

Study design

After negotiation and entry of bronchoscope in the trachea to carina, we have bronchoscopically installed small aliquots of diluted 1% lignocaine. During the bronchoscopy procedure, conventional technique sequences were decided as EBNA first, bronchial wash, bronchial brush, and then FB to avoid contamination due to bleeding secondary to biopsy samplings. Following this sequence as EBNA first also helped us in avoiding false positivity and in some cases with fleshy vascular growth, we have avoided major bleeding by performing EBNA than FB. We have used 22-gauge MW 522 needle catheters (Mill-ROSE Laboratories) during bronchoscopy to perform EBNA procedure. The bronchoscope was moved just proximal to endobronchial growth and the needle with catheter was moved out of scope, then needle was pushed out and introduced into endobronchial lesion. EBNA methodology as classically described in cytology technique “to and fro” used under applied suction from a 20-ml syringe. We have performed 4–5 passages of EBNA samplings during bronchoscopy and stopped the EBNA only after confirmation by assistant and cytopathology technician for adequacy of specimen. We were having a ROSE facility and adequacy of samples was judged during the procedure in the majority of cases. Prepared EBNA cytology slides and fixed with 95% alcohol immediately for the prevention of artefact and to increase the yield. All other bronchoscopic samples (FB and bronchial wash) were sent for cytology and histopathology examination at the Pathology Department.

EBNA cytology images documented during the present study are shown in [Figure 2], [Figure 3], [Figure 4], [Figure 5].

Figure 2: Image showing nonsmall cell carcinoma in endobronchial needle aspiration cytology (Giemsa, ×40)

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Figure 3: Image showing small cell carcinoma in endobronchial needle aspiration cytology (Giemsa, ×40)

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Figure 4: Image showing squamous cell carcinoma in endobronchial needle aspiration cytology (Giemsa, ×40)

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Figure 5: Image showing dysplasia in endobronchial needle aspiration cytology (Giemsa, ×10)

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Statistical analysis

The statistical analysis was done using Chi-square test in R-3.4 software. Significant values of χ² were seen from the probability table for different degree of freedom required. P value was considered significant if it was below 0.05 and highly significant in case if it was <0.001.

Results

Covariates

In the present study, 810 diagnosed lung cancer patients between 29 and 85 years of age group, males are 59.25% (480/810) and females are 40.74% (330/810). In addition history, we have observed 63.20% (512/810) cases are smoker and 43.25% cases with smoking index more than 20 pack years. More common symptoms are cough in 82.09% (665/810), shortness of breath in 46.91% (380/810), hemoptysis in 30.37% (246/810), and chest pain in 16.79% (136/810) cases. Clubbing on general physical examination is documented in 56.17% (455/810) cases. More common radiological presenting features are mass lesion in 42.22% (342/810) cases, hilar opacity in 34.07% (276/810) cases and collapse segmental/lobar in 12.09% (98/810) cases. During bronchoscopy, anatomical location is documented on the right side of tracheobronchial in 59.01% (478/810) cases as compared to the left side of tracheobronchial wall 32.46% (263/810) and growth at carina documented in 8.51% cases (69/810) cases. Upper lobe bronchi are more common site on both sides as compared to other segmental bronchi [Table 1].

Table 1: Clinical evaluation, radiological patterns and anatomical sites during bronchoscopy (n=810)

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Core observations [Table 2] and [Table 3]

Table 2: Diagnostic yield of fiberoptic bronchoscopy-guided procedures in exophytic endobronchial lesions (n=810)

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Table 3: Sensitivity of bronchoscopy-guided endobronchial needle aspiration cytology and forcep biopsy in exophytic endobronchial lesions (n=810)

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In the present study, the yield of FB and FB plus bronchial wash in EEL is 89.25% (723/810) and 93.08% (754/810), respectively. The yield of EBNA, EBNA plus bronchial wash, and EBNA plus FB in EEL is 64.56% (523/810), 67.28% (545/810), and 97.65% (791/810), respectively. The overall yield of all bronchoscopy-guided techniques (EBNA + FB + BW) in our study in EEL is 100%. The additional yield of EBNA in EEL over other CDTs (such as FB plus bronchial wash) is 6.92% [Table 2]. Sensitivity of FB and EBNA in diagnosing lung malignancy in EEL is 89.25% and 64.56%, respectively. FB is more sensitive technique than EBNA in EEL [P < 0.00001, [Table 3]] Sensitivity of FB plus bronchial wash in EEL is 93.08% (754/810). Sensitivity of EBNA plus bronchial wash in EEL is 67.28% (545/810). Sensitivity of EBNA plus FB in EEL is 97.65% (791/810) [P < 0.00001, [Table 4]].

Table 4: Sensitivity of bronchoscopy-guided conventional techniques endobronchial needle aspiration cytology, bronchial wash, and forcep biopsy in exophytic endobronchial lesions (n=810)

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Discussion

Diagnostic yield of endobronchial needle aspiration and endobronchial needle aspiration plus techniques in endobronchial lesions

The total yield of EBNA in EELs is 64.56% (523/810). In our previous published studies^[11],[12] we have documented 62.60% and 60.66% respectively in small sample sizes. Kaçar et al.^[13] observed yield in 77.9% cases. Numerous studies^{[5],[14],[15]} have reported 70%–96% diagnostic yield of EBNA in central airway tumors suspected of bronchogenic carcinoma.

The yield of EBNA, EBNA plus bronchial wash, and EBNA plus FB in EEL is 64.56% (523/810), 67.28% (545/810), and 97.65% (791/810), respectively. Thus, EBNA has documented complimentary role to other conventional diagnostic tests bronchial wash and FB in increasing significant yield. Similarly, studies by Salathé et al.^[17] Caglayan et al.^[18] reported increase in diagnostic yield after adding EBNA to CDTs were 65%–79% and 79%–91%, respectively (P < 0.001). Various authors, Haponik et al.^[10] Gullón et al.^[19] Gellert et al.^[20] observed that the addition of EBNA to conventional diagnostic yield increases the diagnostic sensitivity of bronchoscopy in EELs. They also mentioned that yield is significantly reduced and chances of repeat procedure increased with CDTs without EBNA in presence of endobronchial growth. Similar to our observations, various authors^{[5],[14],[15],[18],[19],[20]} have observed rationale for decreased yield with CDTs possibly due to chance of inadequate sampling during forcep biopsy in presence of superficial necrosis or presence of blood clot over these lesions giving falsely negative biopsy results. Authors^{[5],[14],[15],[18],[19],[20]} have mentioned chances of crush artefacts formation during FB technique resulted in inadequate sampling processed during histopathology, especially during “serrated edges forcep type” in their studies. We have used alligator forcep with needle and rat tooth type to prevent crush artifacts issue in our study. These hurdles of FB resulting in deceased bronchoscopy can be easily tackled with the addition of EBNA to CDTs in diagnostic techniques during the bronchoscopy procedure.^{[5],[14],[15],[18],[19],[20]} The American College of Chest Physicians (ACCP)^[21] guidelines mentioned and recommended TBNA in endobronchial lesions to increase diagnostic yield due to chances of necrotic samplings in cauliflower-type endobronchial growth and to prevent major bleeding with conventional FB use in fleshy hypervascular growth. TBNA will have more value in these two scenarios with EELs. In a literature search, we have found one study by Karahalli et al.^[22] which is not in line to our observations mentioning no added benefit of EBNA to CDTs in increasing diagnostic yield in EELs.

Yield of Forcep biopsy and forcep biopsy plus techniques in exophytic endobronchial lesions

The total yield of FB in EELs is 89.25% (723/810). In our previous published studies,^[11],[12] we have documented 79.67% and 88.18% respectively in small sample sizes. Kaçar et al.^[13] observed yield in 86.4% of cases. Popovich et al.^[16] mentioned that FB is the preferred test during bronchoscopy in EELs with 67%–100% yield and EBNA will not replace FB in these types of lesions.

Table 5: Diagnostic sensitivity of forcep biopsy and endobronchial needle aspiration cytology in exophytic endobronchial lesions

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Sensitivity of forcep biopsy and endobronchial needle aspiration in exophytic endobronchial lesions

Sensitivity of FB and EBNA in diagnosing lung malignancy in EEL is 89.25% and 64.56%, respectively. Thus, FB is considered as gold standard diagnostic technique during bronchoscopy in EELs .

Various authors^[24] have reported the diagnostic sensitivity of FB in endobronchial lesions in absence of EBNA. Author^[24] have reported similar to our findings in their study and reported forcep biopsy as sensitive tool to diagnose lung cancer in endobronchial lesions in absence of EBNA. Author have mentioned sensitivity of forcep biopsy up to 81.6% endobronchial lesions in diagnosing lung malignancy. They have documented superior yield of forcep biopsy and diagnostic sensitivity in comparison to conventional diagnostic techniques (CDTs).^[24]

Additional yield of endobronchial needle aspiration over other methods

The additional yield of EBNA in Exophytic lesions over other CDTs (such as FB plus bronchial wash) is 6.92%.

Shure and Fedullo^[27] studied additional increase in the yield of EBNA to conventional FB. They have reported addition of EBNA to FB has increased diagnostic yield from 55% to 87%.^[27] Numerous authors, Dasgupta et al.^[5] and Bilaçeroğlu et al.^[8] observed increased diagnostic sensitivity of the addition of EBNA to conventional techniques. They have specifically mentioned that EBNA plus CDTs is superior to CDTs alone.^[5],[8]

Sole yield of endobronchial needle aspiration in exophytic endobronchial lesions and importance of rapid on-site evaluation in increasing yield

EBNA was the sole positive test in 52 of total 810 confirmed lung cancer cases [Table 6]. Although FB has diagnosed 723/810 (89.25%) cases and EBNA 523/810 (64.56%) cases, only EBNA is the positive test in 52 cases. In 52 cases diagnosed by cytopathologist in EBNA samples are further processed to immunohistochemistry analysis. All EBNA samples are processed on-site as we are having ROSE facility in our center and this may be the reason for superior diagnostic yield. First published a nonrandomized study documenting the role of ROSE-EBNA performed by Govert et al.^[6] in central neoplasms and they especially mentioned benefits of the ROSE facility in EBNA specimens in increasing yield in endobronchial lesions. A randomized controlled trial done by Mondoni et al.^[28] documented addition of EBNA with ROSA facility will increase diagnostic sensitivity of bronchoscopy in EELs. The author observed significant improvement in sensitivity in ROSE arm than without ROSE in confirming diagnosis, and reported ROSE facility of high importance during bronchoscopy in these lesions in conforming final diagnosis and decreasing need for repeat bronchoscopy procedure.

Table 6: Additional yield of endobronchial needle aspiration cytology, over conventional diagnostic techniques in exophytic endobronchial lesions

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Other important observations in the present study

Histopathology type in the present study: We have documented adenocarcinoma in 36.79% (298/810) cases, Squamous cell carcinoma in 38.51% (312/810) cases, non-small cell carcinoma in 12.71% (103//810) cases, small cell carcinoma in 8.88% (72/810) cases, and large cell carcinoma in 3.4% (25/810) cases. Adenocarcinoma trends are equally observed in histological type as compared to squamous cell type irrespective of smoking trends in study cases. We have documented that EBNA samples have given satisfactory results with histopathology specimens subjected to immunohistochemistry. In adenocarcinoma, 61% cases are epidermal growth factor receptor-positive, 18% anaplastic lymphoma kinase positive, and 12% ROS positive and 9% are all negative
Bronchoscopy procedure and techniques-related complications including EBNA in the present study: Fiberoptic video bronchoscopy-related hypoxia was documented in 36 cases and minor bleeding in 42 cases. Other complications such as significant bleeding, pneumothorax, and death were not seen. Minor bleeding was seen with FB mainly in 5.18% (42/810) cases. EBNA was very well tolerated in nearly all cases without any side effects except minor bleeding in few. Shure and Fedullo^[27] Bollinger et al.^[29] Jin et al.^[30] and ACCP Guidelines on Interventional Pulmonology^[21] reported mortality rate of 0.01% and complication rate 0.7% during procedure and techniques which is comparable with our study. Other potentially life-threatening complications during procedure such as respiratory depression, airway obstruction, arrhythmias and infections were also not observed in our study
In the present study in gender distribution, males were 59.25% (480/810). In addiction patterns, we have observed smoking in 63.20% (512/810) and 43.25% cases in this category were having a smoking index of more than 20 pack years. Despite higher trends of tobacco exposure, adenocarcinoma histology has been documented in significant number with undifferentiated or non-small cell type. Rationale for same findings would be processed tobacco or tobacco with added mixtures of nitrous compounds resulting into predisposition to adenocarcinoma
More common radiological presenting features are mass lesion in 42.22% (342/810) cases, hilar opacity in 34.07% (276/810). Bronchoscopically, anatomical location of lesion was documented on the right side of the tracheobronchial in 59.01% (478/810) cases as compared to the left side of the tracheobronchial wall 32.46% (263/810) and growth at carina documented in 8.51% cases (69/810) cases. Upper lobe bronchi are more common site on both the sides as compared to other segmental bronchi.

Conclusions

EBNA has documented very “crucial role” and should be considered as “complimentary” to CDTs in diagnosing lung cancer in comparison to other CDTs during bronchoscopy in the presence of EELs. Importantly, EBNA samples can give rapid results and decrease chance for repeat procedure by guiding adequacy of samples before end of bronchoscopy procedure.

EBNA is considered safe, especially when fleshy vascular endobronchial growth is present and risk of bleeding is high with FB. EBNA cytology samples can give comparable results to histopathology. EBNA samples are equally processed for immunohistochemistry analysis as histopathology samples. Thus, EBNA is a beneficial, safe and minimally invasive bronchoscopic technique with insignificant side effect in the diagnosis bronchogenic carcinoma.

Although FB is a more sensitive test than EBNA in EEL in diagnosing disease, we have documented EBNA has significant additive yield in proportionate number of cases. The rationale for decreased yield with CDTs in comparison with EBNA is chances of inadequate sampling during FB due to superficial necrosis, blood clot, or crush artefacts resulting into negative yield.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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