A 91-year-old man was introduced to our ward for further examination due to a history of exertional dyspnea for 2 months and the finding of massive right pleural effusion in a general health examination. He had been diagnosed with pleurisy of unknown origin during childhood and had no clear history of exposure to illness.
The patient's vital signs were stable on admission. Chest auscultation revealed reduced breath sounds in the right lower zones. Laboratory investigation showed an elevated level of C-reactive protein (2.39 mg/L) without leukocytosis. Interferon-gamma release assay (T-SPOT ) results were indeterminate. Chest radiography and computed tomography scan of the chest revealed massive right pleural effusion (Fig. 3A and B).
Pleural fluid biochemical analysis revealed that the pleural fluid protein/serum protein ratio was 0.7 with a pleural fluid lactate dehydrogenase level of 180 U/L, indicative of an exudate. Lymphocyte predominance and high adenosine deaminase level (90.1 IU/L) were observed and TB pleurisy was suspected. Sputum and pleural effusion cultures demonstrated no bacterial growth and smears were negative for the presence of acid-fast bacilli. For definitive diagnosis, pleural biopsy was performed via thoracoscopic cryobiopsy (Fig. 3C and D), using a freezing time of 6 seconds. Specimens obtained from the cryoprobe are shown in Fig. 2C and D: these exhibited the size of 0.8 cm; microscopic findings demonstrated epitheloid granulomas with necrosis and many Langerhans type giant cells, highly suggestive of tuberculosis. The Ziehl-Neelsen stain for acid-fast bacilli was negative. Based on the above results, the patient was diagnosed with TB pleurisy. He completed anti-tuberculosis therapy with complete disease remission and will continue follow-up in the Department of Thoracic Medicine outpatient clinic.