A bronchoscopy was performed showing a normal airway. A bronchial washing and transbronchial biopsies of the right middle lobe revealed abundant hemosiderin-laden macrophages. Cultures for bacterial and fungal infections, viruses, and AFB were all negative. Serum markers for autoimmune diseases, such as antinuclear antibody, rheumatoid factor, SM, RNP, SSA, SSB, centromere, scleroderma IgG, and Jo-1 antibodies, were negative. Markers for vasculitides, such as cytoplasmic antineutrophil cytoplasmic antibody, perinuclear antineutrophil cytoplasmic antibody, and glomerular basement membrane antibody, were negative as well. The patient underwent a video-assisted thoracoscopic surgery with right upper, middle, and lower lobe wedge biopsies (Fig 1, 2) due to the lack of diagnosis.