Day #231 - Cavitary Lung Lesions

Today we discussed an immunosuppressed patient with bilateral upper lobe cavitary lung lesions. The differential diagnosis for such lesions in the immunocompetent includes:








Infection:

• TB or Atypical Mycobacterial Disease
• Cavitary Pneumonia
  
  • Gram negatives (Klebsiella, E. Coli, Pseudomonas)
  • Gram positives (Staphylococcus aureus (particularly CA-MRSA), group A streptococci)
  • Anaerobes (Lung Abscess)
• Fungal: Aspergillosis, Histoplasmosis, Coccidiomycosis, Blastomycosis, Cryptococcus
• PCP
  
• Superinfection/Colonization of an existing cavity
  
  • Aspergilloma ("fungus ball" or mycetoma)
• Septic pulmonary emboli with cavitation

Inflammatory:

• Wegner's Granulomatosis
• Rheumatoid Arthritis
• Sarcoidosis (rare)
  

Vascular

• Pulmonary Infarct

Malignancy:

• Bronchoalveolar carcinoma
• Bronchogenic carcinoma
  
• Squamous cell cancer of lung
  
• Cavitating metastases

Anotomical:

• Cystic Bronchiectasis