[Enzyme cytochemical investigations on pleural effusions (author's transl)]

A total of 130 smears from 77 patients with various diseises (42 patients with tumors, 35 patients with specific and non-specific lung diseases) were investigated with enzyme cytochemical methods with regard to the practical application of enzyme cytochemistry in pleural effusions. It is possible to demonstrate all investigated enzymes on normal air-dried or aceton-fixed smears without any technical problems. Between tumor and mesothelial cells a different reaction on some enzymes (alkaline phosphatase, non-specific esterase, aminopeptidase, beta-glucuronidase) could be found valuable for diagnostic purpose. For application in praxi alkaline phosphatase seems to be most important. 70% of all pleural effusions of tumorous origin contain alkaline phosphatase positive tumor cells.