Pulmonary Langerhans Cell Histiocytosis-associated Pulmonary Hypertension Showing a Drastic Improvement Following Smoking Cessation.

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare, smoking-related, interstitial lung disease, and pulmonary hypertension (PH) is associated with mortality. We herein report a case of PLCH complicated by severe PH and respiratory impairment. After developing PH, the patient displayed a cystic pattern on chest high-resolution computed tomography (HRCT). This, in turn, corresponded with the scarring stage of PLCH. However, the patient's PH and respiratory impairment improve dramatically following smoking cessation. PLCH patients with a cystic pattern on chest HRCT may still be able to improve their PH and respiratory impairment when they are able to quit smoking.