A 54-year-old woman presented with a cough, and her examination revealed the following: FEV 1 : 2 L (48% predicted) FVC: 1.47 L (49% predicted) FEV1/FVC: 82% Gas transfer: 54% predicted Transbronchial biopsy: non-caseating granulomas What is the most likely diagnosis for this patient and how would you treat her? *This Case Challenge is from the Editorial Team of Docplexus and is meant for educational purposes only.