Abstract: Objective To analyze the etiology of AIDS complicated with unexplained pleural effusion, and to explore its diagnosis method. Method A retrospective analysis of clinical data such as Clinical manifestations, laboratory tests and histopathology of 30 cases of AIDS with unexplained pleural effusion in our institute between February 2017 to May 2020 was performed. Result Among the 30 AIDS patients with unexplained pleural effusion, 73.3% were diagnosed with tuberculous pleurisy (22/30), 20.0% had malignant pleural effusion (6/30), and 6.7% were undiagnosed(2/30), of which 20 were diagnosed by medical thoracoscopy (MT), 14 were tuberculous pleurisy,6 cases were malignant pleural effusion, and the mt diagnosis rate was 66.7% (20/30). In HIV-positive patients with tuberculous pleuritis, pleural hypertrophy and adhesion are more common under thoracoscopic, the pleural histopathological changes are dominated by lymphocytic infiltration. Granulomas, caseous necrosis and langerhans giant cells are rare. Conclusion Tuberculous pleurisy is the most common in the AIDS complicated with unexplained pleural effusion, the pleural histopathological changes of AIDS complicated with tuberculous pleuritis were mainly lymphocyte infiltration, MT is useful in the diagnosis of AIDS complicated with unexplained pleural effusion.

Key words: Acquired immune deficiency syndrome, Pleural effusion, Thoracoscopy, Etiology, Diagnosis