The tuberculous pleural effusion

Abstract

Pleural tuberculosis (TB) is a common entity with similar epidemiological characteristics to pulmonary TB. It represents a spectrum of disease that can variably self-resolve or progress to TB empyema with severe sequelae such as chronic fibrothorax or empyema necessitans. Coexistence of and progression to pulmonary TB is high. Diagnosis is challenging, as pleural TB is paucibacillary in most cases, but every effort should be made to obtain microbiological diagnosis, especially where drug resistance is suspected. Much attention has been focussed on adjunctive investigations to support diagnosis, but clinicians must be aware that apparent diagnostic accuracy is affected both by the underlying TB prevalence in the population, and by the diagnostic standard against which the specified investigation is being evaluated. Pharmacological treatment of pleural TB is similar to that of pulmonary TB, but penetration of the pleural space may be suboptimal in complicated effusions. Evidence for routine drainage is limited, but evacuation of the pleural space is indicated in complicated disease.

Educational aims: To demonstrate that pleural TB incorporates a wide spectrum of disease, ranging from self-resolving lymphocytic effusions to severe TB empyema with serious sequelae.To emphasise the high coexistence of pulmonary TB with pleural TB, and the importance of obtaining sputum for culture (induced if necessary) in all cases.To explore the significant diagnostic challenges posed by pleural TB, and consequently the frequent lack of information about drug sensitivity prior to initiating treatment.To highlight the influence of underlying TB prevalence in the population on the diagnostic accuracy of adjunctive investigations for the diagnosis of pleural TB.To discuss concerns around penetration of anti-TB medications into the pleural space and how this can influence decisions around treatment duration in practice.

FIGURE 1

Computed tomography image of the thorax showing a right-sided tuberculosis empyema, with significant pleural thickening. Lung entrapment was evident following drainage of the effusion; however, the lung slowly re-expanded over several months.

FIGURE 2

Chylous pleural fluid aspirated from a recurrent chylothorax in a pulmonary tuberculosis (TB) patient. This effusion was likely secondary to paradoxical enlargement of crural lymph nodes following initiation of anti-TB therapy, causing impingement of the thoracic duct in the right hemithorax. The effusion was temporarily managed with indwelling pleural catheter, and ultimately resolved with a combination of anti-TB medications to treat pulmonary disease and immunosuppression to treat the paradoxical reaction.