Objective: Morphologic findings of pulmonary Langerhans' cell histiocytosis were analyzed in order to delineate diagnostic features.
Methods: H&E staining and immunohistochemical studies were performed on 7 cases of pulmonary Langerhans' cell histiocytosis.
Results: Infiltration by Langerhan's cells was obvious in all 7 cases. Inflammatory cell infiltrates, interstitial fibrosis and focal necrosis may also be seen. The cells expressed S-100 (7/7), CD68 (3/7), and CD1a (5/5).
Conclusions: In case there is radiologic suspicion of Langerhans' cell histiocytosis, pulmonary biopsy is strongly advised for a definitive diagnosis. S-100 and CD1a immunostaining is also helpful in this respect.