Brief Discussion

Langerhans cell histiocytosis (histiocytosis X, eosinophilic granuloma)
- Early stage : nodular collections of Langerhans histiocytes and eosinophils (juxtabronchiolar )
- Late stage : fibrosis, honeycombing

- young or middle-aged adults, male predominance, ciagrette smoking history (> 90%), pneumothorax (14%)
- variable PFT pattern/ decreased diffusing capacity
- 60% (lung), 40% (lung + bone, other organ)
- Px : 1/2  favorable, 1/3 stable,  20% progress ( respiratory failure, pulmonary a. HT)

CXR
- nodular, reticulonodular, and cystic abnormalities (upper lung >>)