Differential Diagnosis for Suddenly Bloody Pleural Fluid
- Single most likely diagnosis
- Pulmonary embolism (PE) with pulmonary infarction: This condition is a leading cause of sudden onset of bloody pleural fluid due to the blockage of a pulmonary artery, which can lead to lung tissue infarction and bleeding into the pleural space.
- Other Likely diagnoses
- Malignancy (e.g., lung, breast, or metastatic cancer): Tumors can erode into blood vessels or the pleura, causing bloody effusions.
- Trauma: Both penetrating and blunt trauma to the chest can result in bloody pleural fluid due to injury to the lungs, pleura, or major blood vessels.
- Pneumonia (especially due to Staphylococcus aureus or Klebsiella pneumoniae): Certain bacterial pneumonias can cause necrosis of lung tissue, leading to bloody pleural effusions.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
- Aortic dissection or rupture: Although less common, a tear in the aorta can lead to sudden and catastrophic bleeding into the pleural space.
- Esophageal rupture: This condition can lead to mediastinitis and secondary infection or bleeding into the pleural space, which can be life-threatening.
- Pulmonary arteriovenous malformation (AVM): Rupture of an AVM can cause sudden onset of bloody pleural fluid.
- Rare diagnoses
- Catamenial pneumothorax: A rare condition associated with endometriosis, where menstrual tissue in the pleural space can cause bleeding.
- Pleural endometriosis: Similar to catamenial pneumothorax, but specifically involves the pleura.
- Mitral stenosis with pulmonary venous hypertension: This condition can lead to bleeding into the pleural space, although it is less common and typically associated with other signs of heart failure.