Differential Diagnosis

• Single most likely diagnosis
  • Wegener's Granulomatosis: This condition is characterized by necrotizing arteritis and the presence of granulomas, which are collections of epithelioid histiocytes. The combination of chronic pneumonitis, necrotizing arteritis, and focal collections of epithelioid histiocytes strongly suggests this diagnosis.
• Other Likely diagnoses
  • Sarcoidosis: Although sarcoidosis typically presents with non-necrotizing granulomas, some cases can exhibit necrotizing features. The presence of epithelioid histiocytes is consistent with sarcoidosis, but the necrotizing arteritis is less typical.
  • Churg-Strauss Syndrome: This is an eosinophilic granulomatosis with polyangiitis that can present with necrotizing arteritis and granulomas. However, it is less common than Wegener's Granulomatosis and often associated with eosinophilia and asthma.
• Do Not Miss
  • Infectious Diseases (e.g., Tuberculosis, Fungal Infections): Although less likely, infectious diseases can cause granulomatous inflammation and necrotizing arteritis. Missing these diagnoses could be deadly due to the availability of effective treatments.
  • Malignancy (e.g., Lymphomatoid Granulomatosis): Some malignancies can mimic the described findings, and missing a diagnosis of cancer could have severe consequences.
• Rare diagnoses
  • Rhinoscleroma: A rare chronic granulomatous infection that can affect the lungs and cause similar histological findings.
  • Berylliosis: A rare occupational disease caused by exposure to beryllium, which can lead to granulomatous lung disease.