My father has had a left side unilateral pleural effusion covering down his side and round left side of his back since May 15th CT scan revealed a tumour on left lung. Sample of fluid has been sent for testing and if negative doctor says lung biopsy might have to be next step. Why couldn’t they drain all the fluid then rather than a sample only? And what is the outlook with the pleural effusion I keep reading only months to live but my father is outwardly fit just tired