- What is it:
- Endobronchial nodules refer to
- multiple nodules located
- within the bronchial tree.
- often resulting from
- infectious, inflammatory, or metastatic processes and are
- distinct from
- solitary endobronchial neoplasms.
- Etymology:
Derived from the Greek word bronchos (windpipe) and the Latin prefix endo- (within), indicating the intraluminal location of these nodules.
- AKA:
Multiple intrabronchial nodules.
- How does it appear on each relevant imaging modality:
- Chest X-ray:
- Indirect signs include:
- Airway obstruction with atelectasis or post-obstructive consolidation.
- May show branching opacities if nodules are associated with mucus plugging or inflammation.
- Chest CT:
- Parts: Multiple nodules within the bronchial lumen, occasionally with associated airway thickening.
- Size: Nodules range from 1–10 mm; some may exhibit central cavitation.
- Shape: Round, oval, or irregular, conforming to the airway lumen.
- Position: Confined to the bronchial lumen; often segmental or lobar distribution.
- Character:
- May appear as soft-tissue density (e.g., granulomas or metastatic nodules).
- Associated with airway inflammation or mucus plugging.
- Time:
- Nodules may resolve (e.g., infectious causes) or progress (e.g., metastatic spread or chronic inflammation).
- Bronchoscopy:
- Visualizes multiple intrabronchial nodules, typically as polypoid lesions or clustered growths.
- Allows for sampling to determine the underlying etiology.
- PET-CT:
- Useful for evaluating metabolic activity, particularly in suspected metastatic nodules.
- Differential diagnosis:
- Infection:
- Endobronchial spread of tuberculosis.
- Fungal infections with multiple nodules (e.g., aspergillosis, cryptococcosis).
- Viral or bacterial infections with debris or granulomas.
- Inflammation:
- Allergic bronchopulmonary aspergillosis (ABPA) with mucus and nodular inflammation.
- Bronchocentric granulomatosis.
- Neoplasm (secondary):
- Endobronchial metastases from extrapulmonary malignancies (e.g., renal cell carcinoma, melanoma).
- Immune-related:
- Sarcoidosis with endobronchial granulomas.
- Granulomatosis with polyangiitis (GPA).
- Iatrogenic:
- Retained surgical materials causing inflammatory nodules.
- Congenital or inherited:
- Bronchial atresia with nodular mucus impaction.
- Trauma:
- Granulation tissue secondary to airway injury or instrumentation.
- Recommendations:
- Perform high-resolution CT to determine the number, size, and distribution of nodules.
- Bronchoscopy: Essential for direct visualization and sampling of nodules to determine infectious or malignant causes.
- Obtain microbiological samples (e.g., sputum, bronchial lavage) for suspected infections.
- Consider PET-CT to evaluate for metabolically active or malignant lesions.
- Key points and pearls:
- Emphasis is on multiple nodules, often caused by infectious or metastatic processes rather than primary airway neoplasms.
- Secondary endobronchial involvement from metastases or granulomatous diseases is a critical differential.
- Post-obstructive changes, such as atelectasis or pneumonia, can provide clues to the underlying pathology.
- Resolution of nodules over time may favor benign or infectious causes, while progression may indicate metastatic disease.
