Is bronchoscopic lung biopsy helpful in the management of patients with diffuse lung disease?

To the Editors:

We enjoyed reading the recent retrospective analysis by Ensminger and Prakash 1 of fluoroscopy-guided bronchoscopic lung biopsies (BLB) in patients with suspected diffuse lung disease, which concluded that BLB is a clinically useful test in ∼75% of procedures.

One of the most common indicators for BLB is suspected pulmonary sarcoidosis. In these patients, endobronchial biopsies (EBB) of visible mucosa, in addition to BLB, can be helpful in achieving a diagnosis, even if the mucosa appears macroscopically “normal.” Indeed, some studies from the USA, which included patients of African-American descent, reported diagnostic EBB rates of up to 85%, and, if performed in addition to BLB, increased the diagnostic yield by 21% 2, 3 Our population, in the North-East of Scotland, is predominantly white European, with typically milder endobronchial sarcoidosis. Therefore, we hypothesised that EBB, in addition to BLB, would not be as useful in adding to the diagnostic yield in our patient population.

We reviewed case notes of 54 patients with biopsy proven sarcoidosis, recording data including ethnicity, pulmonary function, chest radiograph staging, biopsy method (BLB±EBB), endobronchial mucosal appearance and procedural complications 4. Patients were all white Europeans, with a mean age of 45 yrs. Mean forced vital capacity was 88% predicted, and the majority of patients had stage II/III disease. All patients had both BLB and EBB. Diagnostic yields from BLB and EBB were 88 and 54% respectively. Additional EBB increased diagnostic yield by only 6%. Diagnosis with EBB was significantly associated with an “abnormal” endobronchial mucosa (p = 0.009) with a positive predictive value of 71%. The diagnostic yield from EBB of normal appearing mucosa was 27%. In total six patients sustained BLB associated pneumothorax.

In conclusion, our data reinforces the view that bronchoscopic lung biopsies are an extremely useful test in the assessment of patients with suspected diffuse lung disease, notably pulmonary sarcoidosis. Furthermore, while additional endobronchial biopsies may not add much to the overall diagnostic yield in white European patients, it is a simple and safe procedure to perform and may confirm the diagnosis in those patients in which bronchoscopic lung biopsy has failed to yield sufficient lung parenchyma for meaningful histological analysis.