Congenital cholesteatoma of the tympanic membrane.

We present two cases of congenital cholesteatoma of the tympanic membrane. Congenital cholesteatoma within the tympanic membrane is a rare entity with only few cases documented. The aetiopathogenesis of this lesion is still unknown. An embryologic origin is hypothesized when cholesteatoma develops in patients without previous history of otitis as in the two cases we report. In cases with previous history of inflammatory process of the external or middle ear an acquired origin is suspected due to the proliferation of the basal cell layer of the tympanic membrane epithelium. Despite the rarity of the congenital tympanic membrane cholesteatoma, we think that its early diagnosis is of utmost importance to allow an easy removal and avoid middle ear involvement.