I. See Also

II. Causes: Most Common

III. Causes: Transudate

  1. See Transudate Pleural Effusion Findings
  2. Congestive Heart Failure
  3. Pneumonia
  4. Nephrotic Syndrome or hypoalbuminemia
  5. Pulmonary Atelectasis
  6. Peritoneal Dialysis
  7. Constrictive Pericarditis
  8. Obstruction of superior vena cava

IV. Causes: Exudate

  1. See Exudate Pleural Effusion Findings
  2. Pulmonary Embolism
  3. Parapneumonic Effusion (Pneumonia with effusion)
    1. Bacterial Pneumonia
    2. Mycobacterium tuberculosis
  4. Malignancy
    1. Lung Cancer (36%)
    2. Breast Cancer (25%)
    3. Lymphoma (10%)
    4. Primary pleural malignancy
  5. Dressler's Syndrome
    1. Post-Myocardial Infarction
    2. Post-Cardiotomy
  6. Gastrointestinal Disease
    1. Esophageal Perforation
    2. Pancreatitis
  7. Intraabdominal abscess
  8. Medications
    1. Methotrexate
    2. Nitrofurantoin
    3. Dantrolene sodium
    4. Methysergide
    5. Procarbazine
    6. Drug-induced Lupus related medications
      1. Procainamide
      2. Hydralazine
      3. Quinidine

V. Causes: Grossly Bloody Effusion (>100,000 cells/cu mm)

  1. See Bloody Pleural Effusion Findings
  2. Trauma (including recent chest surgery)
  3. Pulmonary Embolism
  4. Malignancy
  5. Pneumonia

VI. Causes: Empyema (pus collection, Bronchopleural Fistula)

  1. See Empyema Pleural Effusion Findings
  2. Infection
    1. Pneumonia (50% of empyema causes)
    2. Abscess
      1. Lung Abscess
      2. Subphrenic abscess
    3. Mycobacterium tuberculosis
    4. Fungal infections
  3. Chest trauma (especially penetrating chest wounds)
  4. Spontaneous Pneumothorax

VII. Causes: Other findings

  1. Lymphocytosis
    1. Lymphoma (esp. if >90%)
    2. Mycobacterium tuberculosis (esp. if >90%)
    3. Other causes which less commonly cause Lymphocytosis
      1. Pulmonary Embolism
      2. Post-CABG effusion
      3. Rheumatoid Arthritis
      4. Sarcoidosis
      5. Chylothorax
  2. Loculated Effusion
    1. Empyema
    2. Hemothorax
    3. Tuberculosis
  3. Massive pulmonary effusion
    1. Cancer (represents >50% of cases)
    2. Empyema
    3. Mycobacterium tuberculosis

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