What diagnostic procedure is most likely to confirm the diagnosis in a patient with bilateral hilar adenopathy and diffuse reticular opacities?

The procedure most likely to confirm the diagnosis in a patient with bilateral hilar adenopathy and diffuse reticular opacities is endobronchial lung biopsy. This method is particularly effective for obtaining lung tissue, especially in cases where sarcoidosis or other interstitial lung diseases are suspected, which are commonly associated with the findings described.

Endobronchial lung biopsy allows for direct visualization and sampling of any bronchial involvement, making it a minimally invasive procedure. It is advantageous in patients with hilar adenopathy, as the procedure can be performed during a bronchoscopy, allowing for the assessment of both proximal lung pathology and hilar lymph nodes.

In the context of this presentation, which suggests a likely granulomatous process (such as sarcoidosis), the endobronchial lung biopsy can provide histological confirmation by identifying non-caseating granulomas. This is crucial for establishing a definitive diagnosis and guiding appropriate management.

Other diagnostic methods such as PET scans, pulmonary function tests, or surgical biopsy of mediastinal and lung structures are valuable in assessing lung conditions but are not as definitive for confirming the diagnosis based on the specific clinical context provided. For instance, while a PET scan may aid in identifying metabolic activity in lesions, it does not