Histiocytosis X. Unusual-confusing features of eosinophilic granuloma

We report our experience with seven cases of eosinophilic granuloma in which unusual and/or confusing features were encountered. These features include: histologic confusion with desquamative interstitial pneumonitis, diffuse histiocytic lymphoma, eosinophilic pneumonia; cysts filled with air and/or fluid; radiographic onset in the eighth decade of life; intratracheal mass; and focal parenchymal consolidation.