2010 Jun - The Value of Closed Pleural Biopsies in the Diagnosis of Exudative Pleural Effusions in a Regional General Hospital
Dr. LAM Hong Kei Connie, Queen Elizabeth Hospital
Thoracentesis and closed percutaneous pleural biopsy are common first-line procedures employed to diagnose the aetiologies of exudative pleural effusions. Due to its relatively low yield in non-tuberculous pleural effusions and the emergence of new and more sensitive diagnostic tools, the continued use of closed pleural biopsy has been doubted. This study was carried out to explore the major causes of exudative pleural effusions presented to a general hospital in Hong Kong, as well as the diagnostic performance and complications of the closed pleural biopsy.
This is a single-centre retrospective case record analysis conducted in the Queen Elizabeth Hospital, a regional hospital and tertiary referral centre with thoracic surgical support in Hong Kong. All adult patients admitted to the Department of Medicine in the year 2006 for the investigation of exudative pleural effusions were included and studied. Their clinical records, investigation results and if necessary, the radiographs were reviewed.
A total of 176 patients with exudative pleural effusions were studied, with a mean age of 66.9 17.1 years. The most common diagnoses were malignant pleural effusion (MPE) (52.3%), tuberculous (TB) pleural effusion (22.2%) and parapneumonic pleural effusion (14.2%). No diagnoses were reached in 19 (10.8%) patients. The overall sensitivity and specificity of thoracentesis in all diagnoses were 59.9% and 100% respectively, whilst its sensitivity in the diagnosis of
MPE (78.3%) was noted to be higher than that from a TB origin (46.2%). The sensitivity and specificity of adenosine deaminase (ADA) level (cutoff at 30U/L) in the diagnosis of TB pleural effusion were 97.4% and 59.9% respectively. Closed pleural biopsy was performed in 51 (29%) patients. An overall sensitivity and specificity of closed pleural biopsy for all diagnoses were 53.2% and 100% respectively. Its diagnostic sensitivity in TB pleural effusion (68.2%) was higher than that in MPE (43.5%). Closed pleural biopsy diagnosed TB in 7 out of 13 patients (53.8%) with proven TB effusions and negative pleural fluid findings. In contrast, closed pleural biopsy only diagnosed malignant disease in 2 out of 8 patients (25%) with negative cytological studies of pleural fluid in proven malignant effusions. No significant predictive factor was found to be associated with the yield of closed pleural biopsy. No serious complication was noted for both thoracentesis and closed pleural biopsy. The overall complication rate of closed pleural biopsy was 4%, being one pneumothorax requiring intercostal tube drainage and one self-limiting bleeding from the biopsy site.
Malignant pleural effusions, tuberculous effusions and parapneumonic effusions were the commonest causes of exudative pleural effusions. Closed pleural biopsy can still be of value as a diagnostic tool in the investigation of exudative pleural effusions, especially if TB pleural effusion is suspected and in areas like Hong Kong where TB is prevalent.