Diagnostic yield of medical thoracoscopy in exudative pleural effusions in a region with high tuberculosis burden

Pleural effusion is frequently encountered in respiratory medicine. However, despite thorough assessment including closed pleural biopsy, the cause of around 20% of pleural effusions remains undetermined. Medical thoracoscopy (MT) is the investigation of choice in these circumstances especially if malignancy is suspected. The aim of this study is to evaluate the diagnostic yield of MT in exudative pleural effusions in a single center from East Malaysia.

Retrospective chart review of all adult patients who underwent MT for undiagnosed exudative pleural effusion in a 24-month duration.

Our cohort comprised of 209 patients with a median age of 61 years old (IQR 48.5-69.5). There were 92 (44%) patients with malignant pleural effusion (MPE) and 117 (56%) benign effusions; which included 85 tuberculous pleural effusion (TBE) and 32 cases of non-tuberculous exudative pleural effusion. Conclusive pathological diagnosis was made in 79.4% of the cases. For diagnosis of MPE, MT had a sensitivity of 89.1% (95% CI 80.4-94.3), specificity of 100% (95% CI 96.0-100.0), and positive predictive value (PPV) of 100% (95% CI 94.4-100) and negative predictive value (NPV) of 92.1% (95% CI 85.6-95.9). For TBE, MT had a sensitivity of 90.5% (95% CI 81.8-95.6), specificity of 100% (95% CI 96.3- 100.0) PPV of 100% (95% CI 94.1-100) and NPV of 93.9% (95% CI 88.0-97.2). Overall complication rate was 3.3%.

MT showed excellent sensitivity and specificity in the diagnosis of exudative pleural effusion in this region. It reduces empirical therapy by providing histological evidence of disease when initial non-invasive investigations were inconclusive.