Bloody pleural effusion in septic pulmonary emboli: A presentation of right-sided endocarditis: A report of two cases

Pulmonary embolism is the fourth leading cause of pleural effusion. Pleural effusion that results from a pulmonary embolus is usually small and unilateral. A pulmonary embolus is the most common cause of pleuritic chest pain and pleural effusion in patients aged under 40 years. The incidence, characteristics, and pathogenesis of pleural effusions in patients with right-sided endocarditis (RSE) are poorly defined. Possible mechanisms of pleural fluid formation in RSE include parapneumonic effusion, septic pulmonary emboli with or without infarction, and empyema. We report 2 cases of bloody pleural effusion, combined with septic pulmonary emboli and dyspnea, as the initial manifestation of right-sided endocarditis.