[Neuron-specific enolase in pleural effusions of various etiologies].

The concentration of neuron-specific enolase (NSE) was measured in the serum and pleural fluid of 42 patients with pleural effusions of different etiology. High levels (above 13.0 micrograms/l) of NSE in pleural fluid of 9 patients with malignant disease were observed (sensitivity 57%). However, pleural fluid NSE levels were also increased in 14 with non-malignant diseases (specificity 45%). Increased pleural fluid NSE activity is not specific for malignancy.