The pleural biopsy results when unknown origin pleural effusion

Abstract

Background: The pleural biopsy is an essential evidence-based diagnostic method for the diagnosis, clinical evaluation, and prevention of complications of unknown origin thoracic pleural effusion. Method: In the study, we sampled cases of unknown cause pleural effusion at the TB clinic of National Center for Communicable Disease (NCCD) in 2019-2020 and analyzed their demographic indications, clinical situation, imaging, pleural fluid analyses, pathogen detection, and histological findings. The pleural biopsy was performed by Kerrison bone punch with thoracotomy. Result: A total of 38 cases were included in the study then 24 (63.2%) cases were male, 14 (36.8%) cases were female, the average age was 43.4±15.3. Also, 24 (63.2%) were from Ulaanbaatar and 14 (36.8%) were from rural areas. In 22 (57.9%) cases of the study participants, TB confirmed by biopsy. There was an interesting result that 14 (63%) cases of the total participant's activity level of ADA (adenosine deaminase) enzyme was less than <38U/L in pleural fluid. The 22 (57.9%) TB confirmed cases by biopsy sample sent to bacteriology confirmation then 3 (13.6%) cases were by smear, 6 (27.2%) cases by were Xpert MTB/RIF, and 3 (13.6%) cases by culture M.tuberculosis complex positive. In the duplicated, 7 (31.8%) cases were bacteriologically confirmed. Conclusion: The cause of TB is the majority among the unknown origin pleural effusion. If the threshold for TB-related effusion level (ADA ≥38U/L) less than the threshold does not rule out a diagnosis of TB in which case a pleural biopsy is appropriate.