Differential Diagnosis

The provided radiological findings suggest a range of potential diagnoses. Here's an organized approach to the differential diagnosis:

• Single Most Likely Diagnosis
  • Idiopathic Pulmonary Fibrosis (IPF): The presence of subpleural honeycombing, patchy areas of coarse interstitium, and ground-glass densities, particularly in the lower lobes, is highly suggestive of IPF. This condition is characterized by a progressive and irreversible decline in lung function.
• Other Likely Diagnoses
  • Chronic Hypersensitivity Pneumonitis: This condition can present with similar radiological findings, including ground-glass opacities and fibrosis, often related to exposure to specific antigens.
  • Connective Tissue Disease-associated Interstitial Lung Disease (CTD-ILD): Conditions like rheumatoid arthritis, scleroderma, and lupus can cause interstitial lung disease with findings similar to those described.
  • Asbestosis: Given the presence of pleural and parenchymal findings, asbestosis should be considered, especially if there's a history of asbestos exposure.
• Do Not Miss Diagnoses
  • Lymphangitic Carcinomatosis: Although less likely, this condition can cause diffuse pulmonary infiltrates and should be considered, especially with the presence of shotty lymph nodes.
  • Sarcoidosis: Given the lymph node involvement and potential for pulmonary findings, sarcoidosis is a diagnosis that should not be missed, despite its lower likelihood based on the provided description.
  • Infection (e.g., Tuberculosis, Fungal Infections): Certain infections can cause chronic pulmonary changes and lymphadenopathy, making them important not to overlook.
• Rare Diagnoses
  • Langerhans Cell Histiocytosis: This rare condition can cause cystic and nodular lung lesions, often with upper lobe predominance, but can occasionally present with more diffuse involvement.
  • Eosinophilic Granuloma with Polyangiitis (Churg-Strauss Syndrome): A rare autoimmune condition that can cause asthma, eosinophilia, and vasculitis, potentially leading to pulmonary infiltrates and fibrosis.

Next Steps

1. Correlate with Clinical History: Understanding the patient's symptoms, occupational history, and any previous exposures is crucial.
2. Review Prior Imaging: Comparing current findings with previous imaging studies can help assess disease progression.
3. Pulmonary Function Tests (PFTs): Performing PFTs can provide valuable information on lung function and help differentiate between various causes of interstitial lung disease.
4. Serological Tests: Depending on the clinical suspicion, tests for connective tissue diseases or other autoimmune conditions may be warranted.
5. Consider Biopsy: In some cases, a lung biopsy may be necessary to establish a definitive diagnosis, especially if the diagnosis remains unclear after initial evaluations.