On the interpretation of atypical cells in pleural and peritoneal effusion.

A histochemical method demonstrating the cellular amount of non-specific esterase is applied in the cytologic examination of pleural and peritoneal effusions concerning the recognition of malignant cells. Because of the presence of both false positive and false negative results it is concluded that the method is not conclusive of the benign or the malignant nature of the atypical cells found, but the method may be of value in certain cases.