Malignant pleural effusions. A clinical cytopathologic study.

From 1978 to 1982, 620 pleural fluid cytology specimens were examined, of which 80 were positive in 64 patients. Of these 64, three (0.5%) specimens had false-positive results. Adenocarcinoma of the lung was the most frequent (25 of 61) primary site, followed by breast (12 of 61), ovary (six of 61), and pancreas (five of 61). Comparing cytology with pleural core needle biopsy specimens in 26 patients, the cytology results were positive in 96%, while the needle biopsy specimens alone were positive in only 69%. Following the diagnoses of malignant pleural effusions, the patients receiving combined chemotherapy and radiotherapy had a mean survival of 328 days, compared with only 79 days for those who received no therapy. In conclusion, cytologic examination of Papanicolaou-stained smears yielded a greater percentage of positive diagnoses than either cell block preparations or pleural needle biopsy specimens. Over the past 25 years, the mean survival after the diagnosis of malignant pleural effusions has shown no improvement.