I have got a pt who is a known case of ischaemic heart disease and T2DM, presented with precordial chest pain. On examinations and on investigations, it revealed that it is non cardiac origin and having large pleural effusion in left side.He had a history of pulmonary tuberculosis 10 yrs ago, for which he had been treated and declared cured. But no document provided.

Pleural fluid analysis revealed sligtly increased sugar level and high increase of  protein level with ADA negetive for tuberculosis and 90% lymphocytes rest are polymorphs. what should be the cause of pleural effusion?