Needle biopsy of the pleura in the diagnosis of pleural effusion.

Needle biopsy of the parietal pleura was undertaken in 64 patients with undiagnosed pleural effusion. An adequate specimen was obtained in 96% of procedures. This was diagnostic in 45% of those due to malignancy and in 50% of those due to tuberculosis. A second biopsy improved the combined diagnostic yield in these two diseases from 32% to 46%. Pleural fluid cytology was unhelpful in establishing the presence of a malignancy, and culture of the biopsy specimen was helpful in one case.