Cholesteatoma of the frontal and ethmoid areas.

Cholesteatomas of the frontoethmoid region must always be considered in the differential diagnosis of a mass in the frontoethmoid region. A painless, slow-growing mass, often accompanied by proptosis and diplopia, but without history of trauma or infection, should make one suspect of this pathologic entity. Although histologically a benign lesion, the keratinizing squamous epithelial lining will continue to desquamate and expand, leading to erosion of surrounding structures which could be life-threatening. In order to prevent recurrence, complete removal of the cyst lining is mandatory. Cosmetic reconstruction, often requiring obliteration of the surgical cavity, should be delayed for one year to insure against recurrence of the covering of active squamous tissue adjacent to dura, cribriform plate or ocular structures.