causes of pleural effusion

Etiology

• Osmotic (generally transudative)
  • congestive heart failure
    • most common cause of transudative pleural effusion
    • diuretic therapy may increase pleural fluid LDH causing pseudo-exudative by Light's criteria
  • cirrhosis with ascites
  • obstruction of superior vena cava
  • constrictive pericarditis
  • hypoalbuminemia
  • salt-retaining syndromes
  • peritoneal dialysis
  • hydronephrosis
  • nephrotic syndrome
• Infection (generally exudative)
  • parapneumonic (bacterial) effusions
    • most common cause of exudative pleural effusion
  • bacterial empyema
  • tuberculosis: tuberculous pleural effusion (WBC >= 80% lymphocytes)
  • fungal infection (WBC >= 80% lymphocytes, > 10% eosinophils)
  • parasitic infection - Paragonimus (> 10% eosinophils)
  • viral infection
  • Mycoplasma infection
• Neoplasm (generally exudative, WBC lymphocyte predominant)
  • primary & metastatic lung cancer
  • lymphoma
    • WBC ~100% lymphocytes (non-Hodgkin's lymphoma)
    • > 10% eosinophils (Hodgkin's disease)
  • leukemia
  • benign & malignant pleural tumors
  • intra-abdominal tumors with ascites
  • carcinoma (> 10% eosinophils)
• Vascular disease (generally exudative)
  • pulmonary embolism
    • small, sterile, hemorrhagic, exudative pleural effusion
    • mesothelial hyperplasia
    • > 10% eosinophils
  • Wegener's granulomatosis
• Connective tissue diseases
  • systemic lupus erythematosus
    • acute & chronic inflammatory cells (LE cells)
    • high titers of antinuclear antibody
    • low titers of complement
  • rheumatoid arthritis
    • mixed inflammatory cells (WBC >= 80% lymphocytes)
    • low glucose (< 30 mg/dL)
    • slender, elongated spindle-shaped cells (macrophages)
• Intra-abdominal diseases (generally exudative)
  • pancreatitis & pancreatic pseudocyst (especially, left-sided)
  • subdiaphragmatic abscess
  • malignancy with ascites
  • Meigs' syndrome (generally transudative)
  • hepatic cirrhosis with ascites (generally transudative)
    • hepatic hydrothorax
• Trauma (generally exudative)
  • hemothorax (> 10% eosinophils)
  • chylothorax (WBC >= 80% lymphocytes, triglycerides > 100 mg/dL)
  • esophageal rupture
  • intra-abdominal surgery
  • post CABG, > 2 months after surgery (WBC >= 80% lymphocytes)
• Miscellaneous (generally exudative, unless otherwise indicated)
  • drug-induced effusions (> 10% eosinophils)
    • nitrofurantoin
  • uremic pleuritis (WBC >= 80% lymphocytes)
  • myxedema (generally transudative)
  • yellow nail syndrome (WBC >= 80% lymphocytes)
  • Dressler's syndrome
  • decreased intrapleural pressure
    • atelectasis (generally transudative)
  • erosion of central venous catheters into the mediastinum (generally transudative)
  • pulmonary infarction
  • sarcoidosis (WBC >= 80% lymphocytes)
  • dural pleural fistula (generally transudative)
  • extravascular migration of central venous cather (generally transudative)
  • unilateral obstructive uropathy may result in unilateral pleural effusion (generally transudative)
  • bladder irrigation (generally transudative)
  • trapped lung, unexpandable lung (generally transudative)
  • acute post lung transplant rejection (WBC >= 80% lymphocytes)
  • benign asbestos pleural effusion (> 10% eosinophils)
  • Churg-Strauss syndrome (> 10% eosinophils)
  • pneumothorax (> 10% eosinophils)
• Pharmaceuticals
  • nitrofurantoin (acute)
  • methysergide (chronic)
  • drug-induced lupus erythematosus
  • chemotherapeutic agents
  • radiation
  • dantrolene
  • busulfan

More specific terms

• high-amylase pleural effusion
• low pH pleural effusion (<7.30)
• pleural effusion lymphocytosis