Case of pulmonary Langerhans cell histiocytosis presenting as ground-glass opacity in the lower lung.

Nodules and cysts with upper lobe predominance on chest computed tomography (CT) are highly suggestive of pulmonary Langerhans cell histiocytosis (PLCH). Herein, we describe a case of PLCH that presented with the unusual CT findings of subpleural ground-glass opacity (GGO) and traction bronchiectasis mostly in both lower lungs. No nodules or cysts were observed in the upper or middle lung areas. Video-assisted thoracoscopic biopsies were performed at the right lower lobe. Biopsy specimens showed findings consistent with those of scarred PLCH. To the best of our knowledge, this is the first case of PLCH presenting as GGO in the lower lungs.