Fibroblast Foci and Patchy Fibrosis Do Not Separate Usual Interstitial Pneumonia From Fibrotic Hypersensitivity Pneumonitis in Transbronchial Cryobiopsies

To the Editor.--Although many pulmonologists are adopting transbronchial cryobiopsy, there is a remarkable dearth of information on the specific pathologic features used to diagnose various forms of interstitial lung disease [...]