Comparison of the clinical diagnostic value between pleural needle biopsy and analysis of pleural effusion.

BACKGROUND: Many diseases are manifested by pleural effusion. Chest echo-guided thoracentesis and pleural biopsy are the two major procedures in diagnosing pleural effusion, but the validity is still under debate. To compare the diagnostic value of echo-guided pleural biopsy with pleural effusion analysis, we designed this retrospective study. METHODS: We reviewed 176 patients who underwent both procedures at Chang Gung Memorial Hospital from 1989 to 1990. RESULTS: Sixty-six patients (38%) were diagnosed with malignant pleural effusion which was proven by needle biopsy (55%) or effusion cytologic analysis (64%). Combining both methods increased the diagnostic rate to 88%. Among the 76 patients who were diagnosed with tuberculous pleural effusion, only 18% were proven by pleural biopsy and 20% by pleural effusion culture. The other cases were confirmed by sputum exam (34%) or successful therapeutic trial (41%). The remaining 19 patients (11%) were diagnosed as undeterminate etiology. CONCLUSION: Combined pleural biopsy with cytologic analysis of the pleural effusion was more beneficial than any single method in identifying malignant pleural effusions, and repeated pleural biopsy increased the positive rate from 49% to 55% in our study.