Etiological Distribution and Morphological Patterns of Granulomatous Pleurisy in a Tuberculosis-prevalent Country

The cause of epithelioid granulomatous inflammation varies widely depending on the affected organ, geographic region, and whether the granulomas morphologically contain necrosis. Compared with other organs, the etiological distribution and morphological patterns of pleural epithelioid granulomas have rarely been investigated. We evaluated the final etiologies and morphological patterns of pleural epithelioid granulomatous inflammation in a tuberculosis (TB)-prevalent country. Of 83 patients with pleural granulomas, 50 (60.2%) had confirmed TB pleurisy (TB-P) and 29 (34.9%) had probable TB-P. Four patients (4.8%) with non-TB-P were diagnosed. With the exception of microbiological results, there was no significant difference in clinical characteristics and granuloma patterns between the confirmed TB-P and non-TB-P groups, or between patients with confirmed and probable TB-Ps. These findings suggest that most pleural granulomatous inflammation (95.2%) was attributable to TB-P in TB-endemic areas and that the granuloma patterns contributed little to the prediction of final diagnosis compared with other organs.