Investigation of pleural effusion: comparison between fibreoptic thoracoscopy, needle biopsy and cytology.

Twenty-eight patients with exudative pleural effusion have been investigated by fibreoptic thoracoscopy, Abrams needle biopsy and pleural fluid cytology. Sixteen patients had previously had negative pleural biopsies and cytology. Twenty effusions were malignant (16 mesothelioma, four metastatic carcinoma), seven were due to nonspecific inflammation and in one case no abnormality was found. The diagnostic yield for all three techniques combined was 85%, for thoracoscopy alone 65%, Abrams biopsy 60% and cytology 45%. In 12 patients presenting without previous investigation all eight malignant effusions were correctly diagnosed by at least one of the techniques with individual sensitivities of 75% for thoracoscopy, 63% for Abrams and 38% for cytology. Of the 16 patients who had previously had negative investigations 12 had malignant effusions, nine (75%) of which were diagnosed by a combination of the techniques. In this group, the individual sensitivities were 58% for both thoracoscopy and Abrams and 50% for cytology. A correct diagnosis of malignancy was made by a combination of needle biopsy and cytology in 75% of patients with previous investigations and 88% of those without. Fibreoptic thoracoscopy added only two diagnoses of malignancy to those obtained by Abrams and cytology. The limitations of the technique render it unsuitable for routine investigation of pleural effusions.