Lung Nodules: Is a Bronchoscopy Always Necessary?
"New research sheds light on when a preoperative bronchoscopy might not be beneficial for persistent ground-glass nodules."
The detection of pulmonary nodules, small spots on the lungs, is a common and often worrying clinical issue. As a result of more frequent and advanced imaging techniques, particularly low-dose chest computed tomography (CT) scans, more of these nodules are being discovered. While many are benign, some can indicate early-stage lung cancer, making their evaluation crucial.
Persistent ground-glass nodules (GGNs) are a specific type of pulmonary nodule characterized by their hazy appearance on CT scans. These nodules can represent various conditions, including focal fibrosis (scarring), premalignant lesions, or subtypes of adenocarcinoma, a common type of lung cancer. Unlike solid nodules, GGNs can be challenging to diagnose without invasive procedures, often requiring long-term monitoring to determine their nature.
Traditionally, before surgical removal of lung nodules, a procedure called flexible bronchoscopy (FB) is performed to examine the airways and collect tissue samples. However, the utility of FB in the preoperative assessment of GGNs has been a topic of debate. This article examines the findings of a recent study investigating whether routine preoperative FB is always necessary for patients with persistent GGNs, potentially reducing the need for invasive procedures in select cases.
Nodule Types and Management Uncertainty
Pulmonary nodules are classified as solid or subsolid, with subsolid nodules further divided into part-solid and pure ground-glass types; management strategies differ by type, according to the New England Journal of Medicine review. For screening-detected ground-glass nodules, increased detection with low-dose CT has created a management challenge, and the review reports that there is no clear plan after detection. Clinicians must weigh limiting overtreatment against avoiding delayed care. A separate review notes that malignancy probability rises for excised subsolid nodules measuring 10 mm, and especially those larger than 15 mm.
Long-Term Natural History of Ground-Glass Nodules
Advances in CT technology and findings from the National Lung Screening Trial contributed to increased detection of ground-glass nodules, including on screening CTs and scans after lung resection surgery. A 2013 account of long-term imaging follow-up reported a median time to growth of 5.9 years among 135 pure ground-glass nodules. It also reported that 3.9% of nodules stable for 10 years eventually grew. These findings illustrate why the natural course of pure ground-glass nodules has been studied over extended follow-up.
Bronchoscopy and Ground-Glass Nodules: What the Research Shows
A recent study published in PLOS One investigated the diagnostic value of preoperative flexible bronchoscopy (FB) in patients with persistent ground-glass nodules (GGNs) who were suspected of having lung cancer. The researchers retrospectively analyzed data from 264 patients with 296 GGNs who underwent both preoperative FB and surgical resection.
- Limited Diagnostic Value: Preoperative FB identified malignancy in only 3 of 208 GGNs (1%) examined via bronchial washing cytology, and all three were part-solid GGNs. No other etiology was identified through FB.
- No Change in Surgical Strategy: Routine preoperative FB did not change the planned surgical approach for any patient in the study.
- High Malignancy Rate: Surgical resection subsequently confirmed that 271 of the GGNs (91%) were malignant. The resected malignancies included invasive adenocarcinoma(58%), minimally invasive adenocarcinoma (10%) and adenocarcinoma in situ (23%).
- Benign Cases: The remaining 25 GGNs (9%) were confirmed as benign at surgical resection.
Limited Preoperative Bronchoscopy Yield
A narrative review of subsolid pulmonary nodules reports that, among 264 patients with 296 subsolid nodules who underwent preoperative flexible bronchoscopy, bronchial washing cytology identified malignancy before surgery in only 3 nodules (1%). Another review reports that a retrospective study found fewer than 8% of preoperative bronchoscopies led to unexpected findings, particularly for ground-glass opacities or small non-solid nodules. It also notes that screening-detected lung cancers are often smaller than 2 cm, posing a challenge for conventional bronchoscopy.
Variable Diagnostic Yield and Growth Risk
For persistent ground-glass nodules, one study reports that other studies found bronchoalveolar lavage or washing cytology sensitivities of 29–78% for central lung lesions and 12–65% for peripheral lesions; those studies did not describe lesion characteristics. This limits direct comparison with the study’s own findings. Separately, a 2025 systematic review and meta-analysis concluded that multiple risk factors are associated with ground-glass nodule growth and called for early identification of those factors to guide targeted interventions. Its abstract does not specify the individual risk factors or their effect sizes.
The Future of GGN Management
The study's findings indicate that routine preoperative FB may not be necessary for all patients with persistent GGNs, particularly those with small, pure GGNs. The decision to perform FB should be individualized based on the nodule's characteristics, patient risk factors, and clinical context.
Toward More Accurate GGN Imaging
A 2024 narrative review describes a rapid rise in ground-glass nodule detection, attributing it to advances in imaging technology and greater uptake of screening. It identifies accurate and efficient identification of these nodules as important because ground-glass nodules are a main manifestation of early lung cancer. The review’s stated focus on current imaging status and future directions points to improving imaging-based assessment as an area of ongoing work.
Shared decision-making between physicians and patients is crucial in determining the best course of action. Patients should be informed about the potential benefits and risks of FB, as well as alternative diagnostic and management strategies, such as CT surveillance.
Further research is needed to refine the criteria for selecting patients who may benefit from preoperative FB. Prospective studies using advanced bronchoscopic techniques, such as navigational bronchoscopy, could help improve the diagnostic yield and guide treatment decisions.