[Case of idiopathic bronchiolitis obliterans successfully treated by medication].

A 53-year-old woman visited a clinic for stridor and dyspnea, and was treated with steroid and heparin for bronchial asthma and pulmonary embolism. She was later admitted to our hospital for progressive dyspnea. Blood gas analysis showed severe hypoxemia with hypercapnia. Pulmonary funtion tests revealed severe obstractive pulmonary dysfunction. Chest computed tomography showed a mosaic perfusion pattern. Ventilation-perfusion scanning showed bilateral multiple matched defects, especially in the basal region. Since specimens of Video-assisted thoracoscopic surgical (VATS) lung biopsy showed lymphocytic infiltration in membranous bronchiole and occlusion of the membranous bronchiole lumen, bronchiolitis obliterans was diagnosed. We initiated treatment with steroids, macrolides and bronchodilators and her condition stabilized. Although these therapies did not cure the BO, they did retard its progression.