Spontaneous pneumothorax with isolated pulmonary Langerhans cell histiocytosis in an adult case: A common manifestation of rare disease.

A 30-year-old man presented with sudden chest pain and evidence of multiple cystic lesions in both upper and lower lobes of lungs, as well as left-sided pneumothorax in high resolution computed tomography. In lung samples, hematoxylin and eosin- stained sections and IHC for CD1a, S100, and BRAF V600 were positive. The patient was diagnosed with isolated pulmonary Langerhans cell histiocytosis and was treated accordingly.