Pleural effusion is a common medical problem and it often poses a diagnostic dilemma to the physicians because of its wide range of differential diagnosis. The most important step is to differentiate pleural effusion into malignant or non-malignant group as definite management plan is different. Even after complete diagnostic evaluation including pleural fluid cytology and pleural biopsy, some cases of pleural effusion remain undiagnosed. In such circumstances, measuring pleural fluid tumor markers is not an invasive way and also aids to differentiate malignant from non-malignant cases. Pleural fluid ferritin is one of them that can be used nowadays. So, this study is designed to measure pleural fluid ferritin level in exudative pleural effusion to distinguish into malignant and non-malignant pleural effusion.

A hospital based cross-sectional analytical study was conducted in 85 patients with exudative pleural effusions who underwent diagnostic evaluation in General Medical Wards of Yangon General Hospital, New Yangon General Hospital, and Department of Respiratory medicine, Yangon Speciality Hospital. Among 85 cases of exudative pleural effusions, 49 (57.7%) were malignant pleural effusion cases and 36 (42.3%) were non-malignant pleural effusion cases. Mean pleural fluid ferritin level in malignant pleural effusion (2870.43 +/- 1909 ng/ml) was significantly higher than that in non-malignant pleural effusion (1066.09 +/- 977.13 ng/ml) (p value < 0.001). The optimum cut-off point of pleural fluid ferritin was 1437.7ng/ml with sensitivity of 75.5% and specificity of 77.8% for malignancy. According to this study, pleural fluid ferritin may be a useful tool in aiding diagnosis of malignant pleural effusions.