Role of percutaneous closed needle pleural biopsy among patients of undiagnosed exudative pleural effusion

Background: Sometimes etiological diagnosis of pleural effusion is difficult despite cytological, biochemical and microbiological tests and labeled as undiagnosed exudative pleural effusions. Aim of present study was to make an etiological diagnosis of pleural effusion. Materials and Methods: Study group included patients of exudative pleural effusion where etiological diagnosis could not be yielded by conventional cytological, biochemical and microbiological investigations. Pleural tissue was obtained by Cope′s pleural biopsy needle and or thoracoscopy. Pleural biopsy was subjected to histopathology, ZN staining and culture to find the mycobacterium tuberculosis. Results: Out of 25 patients, 17 (68%) and 8 (32%) were male and female, respectively. Age ranged from 15 to 65 years (mean 31.72). Mean value of serum and pleural fluid LDH was 170.56 U/L and 1080.28 U/L, respectively. Histopathology of 9 (36%) showed epitheloid granuloma with caseation necrosis. In other 9 (36%) patients, epitheloid granulomas (with or without giant cells) was reported. In 5 (20%) patients, histopathology report was of nonspecific chronic inflammation. Histopathology was reported as normal in one case; it turned out to be a case of malignancy. In two (8%) patients, pleural tissue obtained was inadequate for opinions; however, other tests revealed malignancy in one and tuberculosis in other. Ziehl-Neelsen (ZN) stain was positive for AFB in two patients and culture of pleural tissue showed presence of Mycobacterium tuberculosis in three patients. Conclusions: The role of percutaneous closed needle biopsy of pleura among patients of undiagnosed exudative pleural effusion is still accepted as a diagnostic tool, as this may lead to a specific diagnosis among 76% of cases. This is of particular importance in a developing country like India where the facilities of thoracoscopy and imaging guided cutting needle biopsies are not easily available