Pneumothorax



Pneumothorax


Toms Franquet, MD, PhD



DIFFERENTIAL DIAGNOSIS


Common



  • Spontaneous Pneumothorax


  • Traumatic: Blunt or Penetrating Thoracic Injury


  • Iatrogenic


  • Obstructive Pulmonary Disease


  • Interstitial Lung Diseases


  • Connective Tissue Diseases


  • Immunologic


  • Infections


  • Mimics of Pneumothorax


Less Common



  • Metastases


  • Pulmonary Infarction


Rare but Important



  • Catamenial


  • Birt-Hogg-Dubé Syndrome


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Most common symptoms: Sudden dyspnea and chest pain; may be asymptomatic


  • Supine radiographic exams underestimate size and presence of air in pleural space



    • Radiographic findings



      • Deep sulcus sign


      • Hyperlucent anterior costophrenic sulcus over upper abdominal quadrant (subpulmonic)


      • Increased visualization of diaphragm and cardiac contour (anteromedial)


  • Expiratory exam increases proportional size of pneumothorax to hemithorax volume: Aids detection of air in pleural space


  • Spontaneous pneumothorax: Younger adults, tall individuals, and smokers


  • Complications



    • Tension pneumothorax: Life-threatening complication



      • Radiographic findings (contralateral mediastinal shift) + hemodynamic compromise


      • Commonly seen in trauma or mechanical ventilation


    • Reexpansion pulmonary edema



      • Lung reexpansion can cause capillary leak


      • Common after large primary pneumothorax in younger patients


    • Pneumomediastinum



      • Most commonly in neonates


      • In adults being mechanically ventilated


Helpful Clues for Common Diagnoses



  • Spontaneous Pneumothorax



    • Rupture of either small bullae or blebs


    • Familial pneumothorax: Occasionally reported


    • May be treated conservatively with chest tube drainage


  • Traumatic: Blunt or Penetrating Thoracic Injury



    • Pneumothoraces result from alveolar compression, pulmonary laceration, tracheobronchial disruption, and barotrauma



      • Pulmonary lacerations in both blunt and penetrating trauma


      • Persistent pneumothorax due to air-leak or bronchopleural fistula


  • Iatrogenic



    • Complication of biopsy procedures: Transthoracic needle aspiration (underlying emphysema), transbronchial biopsy, and colonoscopy


    • Complication of therapeutic procedures: Thoracentesis, central venous catheterization, mechanical ventilation, and tracheal intubation


    • Mechanical ventilation


  • Obstructive Pulmonary Disease



    • Most common cause of secondary spontaneous pneumothorax


    • Complication of centrilobular or paraseptal pulmonary emphysema, asthma, and cystic fibrosis


  • Interstitial Lung Diseases



    • Lymphangioleiomyomatosis (LAM): Pneumothorax develops in 80% of cases at some point


    • Langerhans cell histiocytosis: Pneumothorax develops in 25% of cases


    • Sarcoidosis



      • Associated with diffuse parenchymal disease


      • Necrosis of a subpleural granuloma


      • Bilateral, recurrent



    • IPF: Pneumothorax or pneumomediastinum develops in 11% of cases


  • Connective Tissue Diseases



    • Rheumatoid arthritis: Necrosis of subpleural necrobiotic nodules


    • Marfan syndrome: Pneumothoraces are commonly bilateral and recurrent; other respiratory abnormalities are bullae, cysts, and emphysema


    • Ehlers-Danlos syndromes: Pneumothorax is common in type IV Ehlers-Danlos syndrome; associated skeletal abnormalities are seen on chest radiograph


  • Immunologic



    • Wegener granulomatosis



      • Usually associated with active vasculitis


      • Subpleural excavated nodules


    • Bronchocentric granulomatosis



      • Necrotizing granulomatous inflammation without associated vasculitis


      • Associated with allergic bronchopulmonary aspergillosis (50%)


  • Infections



    • Bronchopleural fistula: May complicate necrotizing pneumonia (anaerobic, tuberculous, and pyogenic)


    • Postinfectious pneumatoceles resulting from P. jiroveci or Staphylococcus


    • Angioinvasive aspergillosis: Hematogenous dissemination with invasion of small arteries, vascular occlusion and often infarction



      • Particularly common in neutropenic stem cell transplant patients


    • Immunocompromised HIV(+) patients



      • P. jiroveci


  • Mimics of Pneumothorax



    • Skin-folds, chest tube tracks, scapular edge, and rib companion shadow


Helpful Clues for Less Common Diagnoses



  • Metastases



    • Metastatic sarcomas: Osteosarcoma, synovial cell sarcoma, angiosarcoma, and leiomyosarcoma



      • Frequently after induction of chemotherapy


  • Pulmonary Infarction



    • Septic and aseptic emboli



      • Infective endocarditis in intravenous drug users


Helpful Clues for Rare Diagnoses

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Aug 8, 2016 | Posted by in CARDIOLOGY | Comments Off on Pneumothorax

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