Propylthiouracil-induced bronchiolitis obliterans organizing pneumonia.

Propylthiouracil (PTU) is commonly used to treat hyperthyroidism. However, it is also associated with a number of adverse events. In particular, pulmonary complications, although rare, can be serious. Therefore, early detection is paramount. We herein describe a first case of PTU-induced bronchiolitis obliterans organizing pneumonia (BOOP) pathologically confirmed on a surgical lung biopsy. The present case shows that early detection coupled with the immediate withdrawal of PTU can lead to a successful resolution of symptoms and radiographic abnormalities without the need for corticosteroids. Although rare, PTU-induced BOOP should be considered in the differential diagnosis of pulmonary opacity in patients receiving PTU therapy.