Chylothorax with Transudate: An Unusual Presentation of Tuberculosis

INTRODUCTION: Twenty-five per cent of tuberculosis patients have pleural tuberculosis, which is the third most common form of presentation. Most cases present as an exudative pleural effusion with just few cases reported as chylothorax in the literature. All pleural effusions from confirmed cases, including tuberculous chylothorax, had exudate features. AIM: To describe a patient with Mycobacterium tuberculosis affecting the lungs and pleura, which laboratory testing demonstrated had features of transudate chylothorax. PATIENT AND METHODS: A 70-year-old man presented with constitutional symptoms, progressive exertional dyspnoea and right pleural effusion with fibrocavitary changes on chest imaging. Thoracentesis and pleural fluid analysis revealed chylous fluid with transudate features, high triglycerides, low cholesterol content and mononuclear cell predominance. Acid-fast sputum stains and pleural fluid were negative for Mycobacterium tuberculosis as was an adenosine deaminase test for pleural effusion. Tomography-directed lung biopsy sampling of a lung nodule revealed a chronic granulomatous inflammatory process associated with the presence of acid-fast bacilli. DISCUSSION: Tuberculosis-associated chylothorax is an uncommon presentation of the disease. A recent review found only 37 cases of confirmed tuberculous chylothorax had been reported in the literature. All cases had exudate characteristics. The diagnosis of pleural tuberculosis was made through culture or testing of sputum, pleural fluid or biopsy samples in 72.2% of cases, with the rest identified by histopathology. LEARNING POINTS: The main cause of non-traumatic chylothorax is malignancy, which is found in 39–72% of cases. Few cases of transudative chylothorax have been reported in the literature; the main aetiology is chronic hepatopathy. Tuberculosis-associated chylothorax is a rare presentation of infection caused by Mycobacterium tuberculosis, an uncommon aetiology.