Transudative Pleural Effusion as a Rare Manifestation of Disseminated Tuberculosis With Tubercular Myocarditis: A Case Report

Tuberculosis (TB) remains a major public health burden, particularly in India, and is known for its wide spectrum of clinical presentations ranging from pulmonary to extrapulmonary disease. Pleural effusion is a well-recognised complication of TB and is characteristically exudative in nature. We report a rare case of a 27-year-old immunocompetent female patient who presented with a right-sided pleural effusion that was transudative by Light's criteria. Rather than excluding TB, clinical suspicion was maintained, leading to a thorough diagnostic workup. The patient was ultimately diagnosed with disseminated TB involving the pleura, mediastinal lymph nodes, abdomen, pericardium, and myocardium. The transudative character of the effusion was attributed to cardiac failure secondary to tubercular myocarditis, evidenced by a severely reduced left ventricular ejection fraction of 30%. Thoracoscopy with pleural biopsy and mycobacterial culture confirmed the diagnosis. The patient responded well to antitubercular therapy (ATT) with complete radiological resolution of the pleural effusion. This case underscores that a transudative pleural effusion does not exclude TB and that thoracoscopy should be considered when clinical suspicion remains high despite atypical biochemical findings.