<prompt> True regarding presentation of primary T.B. is :BL pleural effusion with negative Tuberculin test.UL hilar lymphadenopathySustained chronic pyrexiaBL pelural effusion with positive tuberculin test.  <response>: Ans is b ie Unilateral hilar lymphadenopathy Pleural effusion occurs in T.B. as a result of penetration of a few tubercle bacilli into the pleural space from an adjacent subpleural focus. Therefore pleural effusion is usually unilateral because the lesion in T.B. is also unilateral so the tubercle bacilli will reach the pleura of the involved lung onlyTuberculosis is invariably accompanied by involvement of the hilar or mediastinal lymph nodes. 