ABSTRACT
Introduction: Pleural effusion is one of the manifestation of a malignant disease which may be malignant pleural effusion with demonstrable malignant cells in the fluid or para-malignant pleural effusion which is reactive response or due obstruction of lymphatic drainage rather than invasion of pleural cavity. Various modalities are there to investigate this condition including routine microscopy, cytology, biopsy etc. Objective: To understand and compare the utility of cancer ratio, tumor markers, malignant cytology in cases of suspected malignant pleural effusion. Material and Methods: This Case Control Cross sectional study was conducted among patients attending respiratory OPD at Sir Sunder Lal Hospital, BHU, Varanasi, diagnosed with malignant pleural effusion and non-malignant pleural effusion. Results: Significant association was found between Cancer Ratio-Carcinoembryonic Antigen, CEA (p = 0.0069), CEA-Cytology (p = <0.01801)