RESUMO
To evaluate the value of depending on pleural fluid glucose level of less than 40 mg/dl for differentiating whether malignant pleural effusion is due to intrathoracic or extrathoracic tumors. This is a retrospective cross-sectional study in which a total of 69 patients, admitted to our hospital, having malignant pleural effusion due to varying malignancies, were included in this study. According to the final diagnosis, these 69 patients were divided into two groups: intrathoracic tumors [23 patients], and extrathoracic tumors [46 patients]. Chi-square was applied and p-value and confidence intervals were obtained. Sensitivity, specificity and accuracy values were calculated. Glucose level of lower than 40 mg/dl was observed in 8 out of 23 cases of intrathoracic tumors. None of 46 cases of extrathoracic tumors had a value of pleural fluid glucose of less than 40 mg/dl. Accordingly sensitivity, specificity and accuracy values were 35%, 100% and 67% respectively for a cut-off value of 40 mg/dl for pleural glucose. From this study, it is concluded that pleural fluid glucose is a useful test in helping to differentiate the origin of pleural effusion whether it is due to intrathoracic or extrathoracic tumors