Unclassifiable interstitial lung disease: an unresolved diagnostic dilemma

Interstitial lung disease (ILD) classification requires a multidisciplinary review that includes input from an ILD clinician, chest radiologist, and lung pathologist. We report a case of ILD that remained unclassifiable due to discordant clinical, radiological, and pathological findings despite a thorough evaluation that included examination of explanted lung tissue. This case demonstrates that ILD can remain unclassifiable even with a complete evaluation and illustrates one approach to the management of such patients.