Etiology

Infection

Viral

• Acute Hepatitis B (see Hepatitis B Virus, [[Hepatitis B Virus]])
• Cytomegalovirus (CMV) (see Cytomegalovirus, [[Cytomegalovirus]])
• Dengue Hemorrhagic Fever (see Dengue Virus, [[Dengue Virus]])
• Epstein-Barr Virus (EBV) (see Epstein-Barr Virus, [[Epstein-Barr Virus]]): infectious mononucleosis
• Herpes Simplex Virus (HSV) (see Herpes Simplex Virus, [[Herpes Simplex Virus]])
• Influenza (see Influenza Virus, [[Influenza Virus]])
• Lassa Virus (see Viral Hemorrhagic Fever, [[Viral Hemorrhagic Fever]])
• Hantavirus (see Hantavirus, [[Hantavirus]])
• Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus, [[Human Immunodeficiency Virus]])
• Measles (see Measles Virus, [[Measles Virus]])
• Respiratory Syncytial Virus (RSV) (see Respiratory Syncytial Virus, [[Respiratory Syncytial Virus]])

Bacterial

• Actinomycosis (see Actinomycosis, [[Actinomycosis]])
• Bacillus Calmette-Guerin (BCG) (see Bacillus Calmette-Guerin, [[Bacillus Calmette-Guerin]]): disseminated
• Legionellosis (see Legionellosis, [[Legionellosis]])
• Lemierre’s Syndrome (see Lemierre’s Syndrome, [[Lemierres Syndrome]])
• Listeriosis (see Listeriosis, [[Listeriosis]])
• Melioidosis (see Burkholderia Pseudomallei, [[Burkholderia Pseudomallei]])
• Mycoplasma (see Mycoplasma Pneumoniae, [[Mycoplasma Pneumoniae]])
• Nocardiosis (see Nocardiosis, [[Nocardiosis]])
• Parapneumonic Effusion (see Pleural Effusion-Parapneumonic, [[Pleural Effusion-Parapneumonic]])
• Rhodococcus Equi (see Rhodococcus Equi, [[Rhodococcus Equi]]): empyema may occur
• Tuberculosis Pleuritis (see Tuberculosis, [[Tuberculosis]])
• Tularemia (see Tularemia, [[Tularemia]])

Fungal

• Blastomycosis (see Blastomycosis, [[Blastomycosis]])
• Coccidioidomycosis (see Coccidioidomycosis, [[Coccidioidomycosis]])
• Cryptococcosis (see Cryptococcosis, [[Cryptococcosis]])
• Histoplasmosis (see Histoplasmosis, [[Histoplasmosis]])
• Invasive Pulmonary Aspergillosis (see Invasive Pulmonary Aspergillosis, [[Invasive Pulmonary Aspergillosis]])
• Pneumocystis Jirovecii (see Pneumocystis Jirovecii, [[Pneumocystis Jirovecii]])

Parasitic

• Amebiasis (see Amebiasis, [[Amebiasis]])
• Echinococcosis (see Echinococcosis, [[Echinococcosis]])
• Paragonimiasis (see Paragonimiasis, [[Paragonimiasis]])

Neoplasm

• Engraftment Syndrome (see Engraftment Syndrome, [[Engraftment Syndrome]])
• Lung Cancer (see Lung Cancer, [[Lung Cancer]])
• Solitary Fibrous Tumor of Pleura (see Solitary Fibrous Tumor of Pleura, [[Solitary Fibrous Tumor of Pleura]])
• Mesothelioma (see Mesothelioma, [[Mesothelioma]])
• Pleural Metastases (see Pleural Metastases, [[Pleural Metastases]])
  • Acute Lymphocytic Leukemia (see Acute Lymphocytic Leukemia, [[Acute Lymphocytic Leukemia]])
  • Acute Myeloid Leukemia (see Acute Myeloid Leukemia, [[Acute Myeloid Leukemia]])
  • Angioimmunoblastic Lymphadenopathy (see Angioimmunoblastic Lymphadenopathy, [[Angioimmunoblastic Lymphadenopathy]])
  • Breast Cancer (see Breast Cancer, [[Breast Cancer]]): 25% of all cases
  • Chronic Lymphocytic Leukemia (see Chronic Lymphocytic Leukemia, [[Chronic Lymphocytic Leukemia]])
  • Chronic Myeloid Leukemia (see Chronic Myeloid Leukemia, [[Chronic Myeloid Leukemia]])
  • Lung Cancer (see Lung Cancer, [[Lung Cancer]]): 30% of all cases
  • Lymphoma (see Lymphoma, [[Lymphoma]]): 20% of all cases
  • Multiple Myeloma (see Multiple Myeloma, [[Multiple Myeloma]])
  • Ovarian Cancer (see Ovarian Cancer, [[Ovarian Cancer]]): 6% of all cases
  • Sarcomas and Melanoma (see Sarcoma, [[Sarcoma]] and Melanoma, [[Melanoma]]): 3% of all cases
    • Kaposi Sarcoma (see Kaposi Sarcoma, [[Kaposi Sarcoma]])
  • Unknown Primary Malignancy: 6% of all pleural metastatic cases
  • Waldenstrom’s Macroglobulinemia (see Waldenstrom’s Macroglobulinemia, [[Waldenstroms Macroglobulinemia]])

Rheumatologic

• Adult-Onset Still’s Disease (see Adult-Onset Still’s Disease, [[Adult-Onset Stills Disease]]): neutrophil-predominant
• Ankylosing Spondylitis (see Ankylosing Spondylitis, [[Ankylosing Spondylitis]]): rare
• Behcet’s Disease (see Behcet’s Disease, [[Behcets Disease]]): uncommon
• Churg-Strauss Syndrome (see Churg-Strauss Syndrome, [[Churg-Strauss Syndrome]]): 30% of cases
• Hypereosinophilic Syndrome (see Hypereosinophilic Syndrome, [[Hypereosinophilic Syndrome]])
• Microscopic Polyangiitis (see Microscopic Polyangiitis, [[Microscopic Polyangiitis]]): pleural effusion occurs in 10-30% of cases
• Mixed Connective Tissue Disease (MCTD) (see Mixed Connective Tissue Disease, [[Mixed Connective Tissue Disease]])
• Polydermatomyositis (see Polydermatomyositis, [[Polydermatomyositis]]): pleural effusions are rare
• Rheumatoid Arthritis (RA) (see Rheumatoid Arthritis, [[Rheumatoid Arthritis]])
• Sjogren’s Syndrome (see Sjogren’s Syndrome, [[Sjogrens Syndrome]])
• Systemic Lupus Erythematosus (SLE) (see Systemic Lupus Erythematosus, [[Systemic Lupus Erythematosus]])
• Scleroderma (see Scleroderma, [[Scleroderma]])
• Wegeners Granulomatosis (see Wegener’s Granulomatosis>, [[Wegeners Granulomatosis]])

Gastroenterologic

• Acute Pancreatitis (see Acute Pancreatitis, [[Acute Pancreatitis]])
• Chronic Pancreatitis (see Chronic Pancreatitis, [[Chronic Pancreatitis]])
• Esophageal Perforation (see Esophageal Perforation, [[Esophageal Perforation]])
• Esophageal Variceal Sclerotherapy (see Esophageal Varices, [[Esophageal Varices]])
• Abdominal Abscess (see Abdominal Abscess, [[Abdominal Abscess]]): subphrenic abscess, intra-splenic abscess
• Diaphragmatic Hernia (see Diaphragmatic Hernia, [[Diaphragmatic Hernia]])
• Inflammatory Bowel Disease (see Inflammatory Bowel Disease, [[Inflammatory Bowel Disease]])
• Post-Abdominal Surgery
  • Liver Transplant (see Liver Transplant, [[Liver Transplant]])
• Biliary-Pleural Fistula (see Pleural Effusion-Cholethorax, [[Pleural Effusion-Cholethorax]])

Cardiac

• Acute Pericarditis (see Acute Pericarditis, [[Acute Pericarditis]])
• Congestive Heart Failure (see Congestive Heart Failure, [[Congestive Heart Failure]]): borderline exudates may be seen in some long-standing cases
• Post-CABG Pleural Effusion (see Post-CABG Pleural Effusion, [[Post-CABG Pleural Effusion]])
• Post-Cardiac Injury Syndrome (see Post-Cardiac Injury Syndrome, [[Post-Cardiac Injury Syndrome]])

Renal

• Uremic Pleurisy (see Uremic Pleurisy, [[Uremic Pleurisy]])

Reproductive

• Ovarian Hyperstimulation Syndrome (see Ovarian Hyperstimulation Syndrome, [[Ovarian Hyperstimulation Syndrome]])
• Pregnancy (see Pregnancy, [[Pregnancy]]): small amounts of U/S-detected pleural effusion are a normal finding in pregnancy (unclear whether these are transudates or exudates)
• Meig’s Syndrome (see Meig’s Syndrome, [[Meigs Syndrome]])
• Endometriosis (see Endometriosis, [[Endometriosis]])

Drugs

• All-Trans Retinoic Acid (ATRA) (see All-Trans Retinoic Acid, [[All-Trans Retinoic Acid]])
• Amiodarone (Cordarone) (see Amiodarone, [[Amiodarone]])
• Bromocriptine (Parlodel, Cycloset, Brotin) (see Bromocriptine, [[Bromocriptine]])
• Cabergoline (Dostinex, Cabaser) (see Cabergoline, [[Cabergoline]])
• Dantrolene (see Dantrolene, [[Dantrolene]])
• Dasatinib (Sprycel) (see Dasatinib, [[Dasatinib]])
• Docetaxel (Taxotere) (see Docetaxel, [[Docetaxel]])
• Ergotamine (see Ergotamine, [[Ergotamine]])
• Interleukin-2 (IL-2) (see Interleukin-2, [[Interleukin-2]])
• Isotretinoin (Accutane) (see Isotretinoin, [[Isotretinoin]])
• Mesalamine (5-ASA) (see Mesalamine, [[Mesalamine]])
• Methotrexate (see Methotrexate, [[Methotrexate]])
• Methysergide (see Methysergide, [[Methysergide]])
• Metronidazole (Flagyl) (see Metronidazole, [[Metronidazole]])
• Mitomycin C (see Mitomycin, [[Mitomycin]])
• Nitrofurantoin (Macrodantin, Macrobid, Furadantin) (see Nitrofurantoin, [[Nitrofurantoin]])
• Procarbazine (see Procarbazine, [[Procarbazine]])
• Propylthiouracil (PTU) (see Propylthiouracil, [[Propylthiouracil]])
• Sulfasalazine (Azulfidine) (see Sulfasalazine, [[Sulfasalazine]])

Other

• Acute Eosinophilic Pneumonia (see Acute Eosinophilic Pneumonia, [[Acute Eosinophilic Pneumonia]])
• Acute Pulmonary Embolism (see Acute Pulmonary Embolism, [[Acute Pulmonary Embolism]]): 80% of effusions are exudative
• Benign Asbestos Pleural Effusion (see Benign Asbestos Pleural Effusion, [[Benign Asbestos Pleural Effusion]])
• Chylothorax (see Pleural Effusion-Chylothorax, [[Pleural Effusion-Chylothorax]])
• Electrical Burns (see Electrical Burns, [[Electrical Burns]])
• Extramedullary Hematopoiesis (see Extramedullary Hematopoiesis, [[Extramedullary Hematopoiesis]])
• Familial Mediterranean Fever (see Familial Mediterranean Fever, [[Familial Mediterranean Fever]])
• Hemothorax (see Pleural Effusion-Hemothorax, [[Pleural Effusion-Hemothorax]])
• Hypothyroidism (see Hypothyroidism, [[Hypothyroidism]])
• Inadvertent Central Venous Catheter (CVC) Placement Into Pleural Space (see Central Venous Catheter, [[Central Venous Catheter]]): pleural fluid will have characteristics of the infusate, so may appear to be transudative or exudative
• Inadvertent Nasogastric (NG) Tube Placement Into Pleural Space (see Nasogastric Tube, [[Nasogastric Tube]]): pleural fluid will have characteristics of the infusate, so may appear to be transudative or exudative
• Lung Transplant (see Lung Transplant, [[Lung Transplant]])
• Post-PTE Surgery (see Chronic Thromboembolic Pulmonary Hypertension, [[Chronic Thromboembolic Pulmonary Hypertension]]): in cases where pericardial window (with drainage to left pleural space) is created -> usually left-sided
• Radiation Pleuritis (see Radiation Pleuritis, [[Radiation Pleuritis]])
• Sarcoidosis (see Sarcoidosis, [[Sarcoidosis]])
• Trapped Lung (see Trapped Lung, [[Trapped Lung]])
• Trauma
• Yellow Nail Syndrome (see Yellow Nail Syndrome, [[Yellow Nail Syndrome]])

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Diagnosis-Pleural Fluid Criteria (see Pleural Effusion-General, [[Pleural Effusion-General]])

General Comments

• LDH Ratio and Total Protein Ratio are Necessary from Light’s Criteria
  • The pleural LDH <66% criterion does not add more in discriminative value
• Cut-Off Values for LDH and Total Protein Ratios: since there is not a discrete cut-off between values of LDH and total protein, the specified cut-off values give high sensitivity but lower specificity (ie: you will detect all true exudates, but you may misclassify some transudates as exudates, as in diuresed congestive heart failure cases)

Transudate (see Pleural Effusion-Transudate, [[Pleural Effusion-Transudate]])

• LDH Ratio <0.6
• Total Protein Ratio <0.5
• Pleural LDH <66% of Upper Limit of Normal Range for Serum LDH
• Pleural Cholesterol <55-60 mg/L
• Pleural/Serum Cholesterol Ratio: normal
• Serum-Pleural Albumin Gradient (SPAG) >1.2 g/dL
  • If fluid clinically appears to be a transudate and SPAG >1.2, but Light’s criteria suggest exudate, fluid can be assumed to be a transudate (albumin is lower MW than other proteins and crosses capillary walls more easily)

Exudate (see Pleural Effusion-Exudate, [[Pleural Effusion-Exudate]])

• General Comments: pleural effusion is considered exudative if it meets any one of the following criteria, although LDH ratio and total protein ratio are the best criteria
• LDH Ratio >0.6
• Total Protein Ratio >0.5
• Pleural LDH >66% of Upper Limit of Normal Range for Serum LDH
• Pleural Cholesterol >55-60 mg/dL
• Pleural/Serum Cholesterol Ratio: elevated
• Serum-Pleural Albumin Gradient (SPAG) <1.2 g/dl
  • If fluid clinically appears to be a transudate and SPAG >1.2, but Light’s criteria suggest exudate, fluid can be assumed to be a transudate (albumin is lower molecular weight than other proteins and crosses capillary walls more easily)

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References

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