<prompt> Commonest cause of lung abcess -Hematogenous spread from distant siteDirect contactAspirationLymphatic spread  <response>: Routes of infection to lung Aspiration of organisms that colonize the oropharynx MC Inhalation of infections, aerosols Hematogenous dissemination from an extrapulmonary site. Direct inoculation as in tracheal intubation or stab wounds Contiguous spread from an adjacent site of infection. Ref : Harrison 17e p1631 