Organizing pneumonia (OP) is a known non-infectious pulmonary complication following allogeneic hematopoietic cell transplant (HCT) and represents a significant risk factor for non-relapse mortality in HCT recipients. Unlike bronchiolitis obliterans syndrome, it is not universally acknowledged as a distinctive pulmonary manifestation of chronic-graft-versus-host disease (cGVHD) and therefore, its diagnostic criteria and management approach is lacking. Given it shared similar clinical …