Can Tuberculosis Present as a Neutrophilic Pleural Effusion?

Introduction: Tuberculous pleuritis accounts for approximately 10% of tuberculosis cases and represents a significant proportion of extrapulmonary tuberculosis manifestations. This review aims to consolidate current evidence concerning the prevalence, natural course, diagnostic challenges, and treatment responses associated with neutrophilic tuberculous pleural effusions (TPE). Materials and Methods: A comprehensive search of the PubMed database was conducted using specific search terms related to the topic. A total of 67 articles were initially retrieved, with a meticulous screening process ultimately resulting in the inclusion of 8 relevant articles. Results: Tuberculous pleural effusion is traditionally characterized as a lymphocytic exudate. However, some studies have reported the prevalence of neutrophilic TPE to be around 10% or even higher. The differential diagnosis of a neutrophilic pleural effusion can be challenging, as tuberculosis (TB) should not be readily ruled out. Neutrophilic tuberculous pleural fluid exhibits distinct characteristics, including lower pH, elevated lactate dehydrogenase (LDH) levels, increased adenosine deaminase (ADA) levels, and a higher likelihood of positive results in TB-PCR and mycobacterium tuberculosis cultures when compared to the lymphocytic variety. It has been observed that a cutoff value of 5.62 for the ADA/serum CRP ratio provides increased sensitivity and specificity in indicating TPE. Conclusion: The diagnosis of TB relies on a combination of pleural fluid predominantly characterized by lymphocytes and elevated ADA levels. However, this classical presentation is not universal; at times, neutrophilic TPE predominates, complicating the differential diagnosis. Physicians must be aware of this exception to avoid misdiagnosis.