The use of cytology to evaluate pericardial effusions.

Pericardial effusions from 27 patients were examined cytologically during the five-year period of 1973-1977. Malignant cells were found in eight cases (30 percent). In three of these patients malignancy was unsuspected clinically, and this was the first time the cancer was diagnosed. In addition, cytology often suggested the specific histological types and possible primary sites to be determined. Special stains were also found helpful. There were no false positive reports. Although the pericardial effusions from the remaining 19 patients were negative for tumor cells, metastatic carcinoma to the pericardium was discovered at autopsy in two of these cases. Thus, cytologic examination of pericardial fluid is an important tool in the diagnosis of malignancy, but false negative results may occur.