Since its clinical implementation in the early 2000s, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has fundamentally transformed the strategy for mediastinal evaluation in lung cancer. By enabling real-time, ultrasound-guided sampling of mediastinal and hilar lymph nodes through a minimally invasive bronchoscopic approach, EBUS-TBNA has progressively supplanted mediastinoscopy as the primary invasive staging modality in non-small cell lung cancer (NSCLC). When combined with endoscopic ultrasound (EUS), this integrated endosonographic approach provides comprehensive access to virtually all mediastinal lymph node stations, offering diagnostic accuracy comparable to surgical staging with substantially lower morbidity.

The clinical importance of precise mediastinal staging has been further amplified by advances in the tumor, node, metastasis (TNM) classification system. As the prognostic stratification between N2a (single-station N2 involvement) and N2b (multi-station N2 involvement) has become increasingly refined, the distinction between these substages now carries direct therapeutic implications, influencing decisions regarding surgical candidacy, neoadjuvant treatment, and the appropriateness of perioperative immunotherapy strategies. In this context, the accuracy and completeness of mediastinal staging are no longer merely academic; they directly determine each patient's treatment pathway.

Beyond its established role in mediastinal staging, EBUS-TBNA has continued to evolve in both scope and capability. Technological innovations, including third-generation thin scope instruments, novel tissue acquisition devices, and image-based analytical tools, have expanded its diagnostic reach to peripheral lymph nodes, non-nodal lesions, and even extrathoracic sites. Concurrently, the growing demand for comprehensive genomic profiling through next-generation sequencing (NGS) has placed new emphasis on optimizing tissue acquisition strategies to ensure adequate specimen quality.

This review summarizes six key areas of recent advancement in EBUS-TBNA: mediastinal staging strategies with a focus on systematic sampling and the role of confirmatory mediastinoscopy; the expanding reach of thin scope EBUS; novel sampling devices including the 19-gauge needle, mini forceps, and mediastinal cryobiopsy; tissue adequacy for NGS; and image-based adjunctive tools encompassing elastography and artificial intelligence (AI)-driven sonographic analysis.

Positron emission tomography (PET)-computed tomography (CT) plays an important role as a non-invasive tool for mediastinal staging in lung cancer. However, its diagnostic performance is constrained by limited sensitivity and specificity, and no experienced clinician relies solely on PET-CT findings to make definitive treatment decisions [1,2]. To overcome these limitations, current guidelines endorse minimally invasive endosonography, combining EBUS-TBNA and EUS, as the firstline invasive staging modality, replacing mediastinoscopy in the initial evaluation of the mediastinum [3]. The guidelines recommend biopsy of all mediastinal lymph nodes demonstrating abnormal uptake on PET-CT, with subsequent mediastinoscopy reserved for cases in which EBUS-TBNA fails to provide a conclusive result. An important clinical question concerns the management of patients with radiologically N0 disease. Current guidelines recommend EBUS-TBNA for N0 patients with centrally located tumors, tumors larger than 3 cm, or suspected N1 involvement. The clinical significance of this recommendation was reinforced by a large Korean cohort study published in 2025 [4]. This study analyzed approximately 5,000 patients who underwent surgical resection for NSCLC [4]. Among the 3,300 radiologic N0 cases, patients were stratified by the presence or absence of predefined EBUS-TBNA indications. Unforeseen pN2 disease was detected in 5.0% of cases without an indication for EBUS-TBNA, while the prevalence of occult pN2 metastasis rose significantly to 9.0% in those meeting EBUS-TBNA indications. These findings provide compelling evidence that physicians should actively pursue invasive mediastinal staging in patients with predefined EBUS-TBNA indications, even when radiologic evidence of N2 disease is absent. Survival analyses from the same study also revealed prognostic implications. In the group without EBUS-TBNA indications, the mediastinal lymph node metastatic burden appeared to be the predominant factor influencing survival, with clear prognostic differences observed between pN2a and pN2b disease [4].

The incorporation of EUS using the EBUS scope through the esophagus (endoscopic ultrasound using the EBUS scope-fine needle aspiration [EUS-B-FNA]) has broadened the scope of endosonographic staging by allowing access to paraesophageal and pulmonary ligament lymph nodes [5,6]. However, whether routine EUS-B-FNA is warranted in all radiologically N0 patients remains unresolved. Data from the Greater Manchester Cancer center in England provided informative findings on this issue [7]. Their analysis of approximately 1,400 patients who underwent surgical resection showed that nearly half had intraoperative sampling at stations 8 and 9. Of those sampled, approximately 5% had confirmed metastatic disease at these stations. However, only 2% of the entire cohort had N2 disease detectable exclusively through EUS-accessible stations. Furthermore, among patients staged as PET-N0, only approximately 1% had N2 metastasis at stations 8 or 9. These data suggest that routine EUS-B-FNA may not be necessary when PET-CT shows no evidence of disease at stations 8 or 9, although targeted evaluation remains appropriate when imaging abnormalities are identified at these locations.

The need for confirmatory mediastinoscopy after negative EBUS-TBNA in mediastinal staging for lung cancer has been questioned. A landmark randomized controlled trial directly compared immediate surgical resection versus mediastinoscopy followed by surgery in patients with negative EBUS-TBNA results [8]. On intention-to-treat analysis, the unforeseen N2 rate was 8.8% in the immediate resection group and 7.7% in the mediastinoscopy group, representing a reduction of only approximately 1%. Importantly, the addition of mediastinoscopy was associated with significant trade-offs, including surgical delays, procedural complications, and a mortality risk of 0.6% [6]. Long-term follow-up data published in 2025 demonstrated no significant differences in overall survival (OS) or disease-free survival between the two groups, further questioning the clinical value of confirmatory mediastinoscopy [9]. Further evidence emerged from a large retrospective study that examined nearly 4,500 radiologic N0 patients [10]. Of these, approximately 900 underwent invasive mediastinal staging with EBUS-TBNA or mediastinoscopy, while the remainder proceeded directly to surgery. Overall, 7.2% were found to have pN2 disease. After propensity score matching for age, sex, performance status, tumor size, centrality, solidity, forced expiratory volume in 1 second, and 18F-fluorodeoxyglucose uptake on PET-CT, no significant differences were observed between the two groups in OS or recurrence-free survival [10]. Collectively, these data support the position that EBUS-TBNA-negative patients who have undergone systematic nodal sampling may proceed to surgical resection without confirmatory mediastinoscopy.

Two distinct approaches to mediastinal lymph node sampling have been described: targeted sampling and systematic sampling. Targeted sampling involves biopsying only those lymph nodes that appear abnormal on PET-CT or chest CT. In contrast, systematic sampling evaluates all accessible lymph node stations, regardless of imaging findings. While targeted sampling may seem efficient, it carries the inherent risk of missing occult metastatic disease in radiologically normal nodes, potentially leading to understaging of the mediastinum.

Evidence supporting the superiority of systematic sampling has been accumulating. When systematic EBUS combined with EUS sampling is performed, the sensitivity for detecting N2 and N3 disease improves by approximately 9% compared with PET-CT targeted EBUS alone [11]. This improved detection has direct therapeutic consequences. For instance, identifying previously unrecognized N3 disease fundamentally alters the treatment plan from surgical resection to definitive concurrent chemoradiotherapy.

Current evidence recommends a strategic approach to EBUS sampling. For patients with suspected distant metastasis, the sampling site should be chosen to simultaneously diagnose and determine the most advanced disease stage with the lowest procedural risk. The recommended sampling sequence begins with N3 stations, progresses to N2, and then to N1 lymph nodes. At a minimum, routine sampling of stations 4R, 4L, and 7 is required when the short-axis diameter exceeds 5 mm [1]. Stations 8 and 9 should always be inspected on chest CT and evaluated with EUS-B-FNA if abnormalities are suspected, even when PET-CT is unavailable at the time of the procedure (Figure 1).

A significant technological advance in recent years has been the development of third-generation thin scope EBUS instruments. These newer devices feature a reduced outer diameter of 6.6 mm compared to the conventional 6.9 mm, a seemingly modest reduction that nonetheless substantially expands the procedural reach of EBUS-TBNA. The thinner diameter enables access to more peripheral lymph node stations including station 12 (N1) nodes and, in select cases, to peripheral lung nodules and lesions that were previously inaccessible with standard EBUS scopes (Figure 2) [12].

The therapeutic armamentarium for EBUS-guided tissue acquisition has expanded considerably in recent years. Three notable additions—the 19-gauge needle, mini forceps, and mediastinal cryoprobe—each may compensate for specific limitations of conventional EBUS-TBNA and offer distinct advantages in particular clinical scenarios.

The era of precision oncology has placed unprecedented demands on tissue acquisition techniques, as comprehensive genomic profiling through NGS has become integral to therapeutic decision-making in advanced NSCLC. The adequacy of tissue specimens obtained by EBUS-TBNA for successful NGS analysis is, therefore, a question of direct clinical relevance.

Comparative data across biopsy methods reveal a clear hierarchy in NGS success rates. Surgical resection specimens achieve the highest rates of complete molecular profiling, approaching 98% [20]. In contrast, EBUS-TBNA specimens yield successful NGS results in approximately 55% to 64% of cases. This discrepancy reflects the inherent limitations of needle aspiration, including smaller tissue volumes, cellular crush artifact, and blood contamination, all of which can compromise the quality and quantity of DNA available for comprehensive genomic analysis. For CT-guided transthoracic core needle biopsies, larger bore needles have been associated with significantly higher NGS success rates (90% with 18-gauge vs. 33.3% with 20-gauge needles). Although direct comparative evidence regarding NGS success rates between 19- and 22-gauge EBUS-TBNA needles is currently lacking, it is reasonable to extrapolate that larger bore EBUS needles may similarly improve tissue adequacy for comprehensive genomic profiling [20].

Meta-analytic evidence confirms that the success of NGS from EBUS-TBNA specimens is directly proportional to the number of needle passes performed [21]. To maximize the likelihood of obtaining sufficient tissue for comprehensive molecular testing, at least three separate aspirations are recommended. This has important practical implications: bronchoscopists performing EBUS-TBNA in patients with suspected advanced NSCLC should explicitly aim to acquire adequate tissue for both cytological or histological diagnosis and subsequent molecular profiling.

Given the tissue quality limitations of conventional EBUS-TBNA, mediastinal cryobiopsy has emerged as a potential alternative to enhance NGS success rates [22]. Recent data suggest that cryobiopsy yields larger, architecturally preserved tissue specimens [23], which demonstrate improved sample quality and higher NGS success rates compared to conventional EBUS-TBNA [24]. While promising, further prospective comparative studies are needed to establish cryobiopsy's role as a standard approach for molecular profiling in clinical practice.

EBUS-TBNA continues to evolve as a versatile and indispensable tool in thoracic oncology and beyond. The evidence reviewed herein supports several key conclusions relevant to contemporary clinical practice. As innovations converge, the EBUS-TBNA's clinical scope will undoubtedly continue to expand, pushing the boundaries of what minimally invasive diagnostics can achieve. Future research should focus on prospective validation of novel devices in multicenter settings, standardization of sampling protocols for molecular profiling, and integration of AI-based decision support into routine clinical workflows.