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General features of patients with Pulmonary Langerhans Cell Histiocytosis followed in our instution.

Introduction
Pulmonary Langerhans Cell Histiocytosis (PLCH) is a rare disease affecting young smokers. It is more common between the ages of 20-40 and equals the male/female ratio. Lung biopsy is the most useful methods for diagnosis. The first treatment is to quit smoking. Corticosteroids or chemotherapeutic agents can be used in severe progressive cases despite of quiting smoking. The patients with PLCH followed in our clinic were assessed with general clinical features in the light of the literature.


Materials and Methods
We retrospectively evaluated patients with PLCH in our clinic between January 1999 and June 2017.


Result
The female and male distribution of the 21 patients was 11/10. The average age was 35.04 ± 11.78 years. All patients were active smokers at the time of admission. The most common symptom was dyspnea. The most common finding in the pulmonary function tests was obstructive ventilatory defect. The DLCO value of the 70% patient in the carbonmonooxid diffusion test was below 80%. The most common pathologic findings detected in high-resolution chest tomography (HRCT) were cystic lesions involving bilateral upper and middle areas. There were 3 (14%) patients with pneumothorax at the time of admission and 6 (28.5%) patients with pneumothorax history before. The most common diagnostic method was open lung biopsy. All the patients quit cigarette after the diagnosis. There were 6 patients using steroid therapy, 1 patient receiving steroid and bosentan therapy, and 1 patient made pleurectomy due to recurrent pneumothorax. Lung transplantation was done to patient who received combined bosentan treatment with steroids.


Conclusions
PLCH is a rare disease and should be considered in young, smokers with spontaneous pneumothorax and cystic lung disease in the differential diagnosis. As more diffusions are affected in patients, respiratory functions for follow-up should be evaluated with diffusion tests. It is essential to quit smoking in therapy.