Bronchoscopy in the diagnosis of pulmonary blastomycosis

Diagnosing pulmonary blastomycosis (PB) requires the detection of Blastomyces dermatitidis in pulmonary secretions or tissue, which can be achieved via bronchoscopic procedures like bronchoalveolar lavage (BAL) or brush and transbronchial biopsy (TBBx). This descriptive study retrieved the data of PB that was diagnosed by bronchoscopy to define which bronchoscopic procedure produced the highest yield.

Retrospectively, all patients diagnosed with PB via bronchoscopic approach were identified. Non-invasive BAL was referred to when performed first in the order of bronchoscopic procedures, and invasive BAL was used when it was performed after other bronchoscopic procedures.

A total of 111 patients were included in the study. BAL produced the highest yield of all bronchoscopic procedures (>87%), regardless if it was performed first in order (non-invasive, 87.3%) or not (invasive BAL, 89.6%) (p = 0.43). Performing bronchoscopy and BAL earlier in the course of the disease resulted in a significantly better diagnostic yield.

BAL is probably enough to diagnose PB. Also, it had the best yield when performed earlier, regardless of whether it was performed first in order or not. BAL culture had a better yield in detecting Blastomyces dermatitidis over fungal stain and cytology.