A review of twenty congenital cholesteatomas of the middle ear in children.

Cholesteatomas, arising within the middle ear space behind an intact tympanic membrane, have been detected more frequently in recent years. This article reviews 19 children (with a mean age of 4.3 years) who underwent surgery over a 7-year period for removal of cholesteatomas from behind intact tympanic membranes. Most of these children were referred by pediatricians who had detected an asymptomatic whitish middle ear mass. Many had histories of treatment for otitis media. Patients with similar histories were excluded from the series if there had been a prior perforation, myringotomy, or otologic surgery. In the series, one fourth of the children had associated congenital malformations, and there were 3 times as many boys as girls. In two thirds of the cases, the cholesteatoma was manifested as an anterior-superior middle ear mass that seemed to arise from the processus cochleariformis, undersurface of malleus area. Many could be removed via an extended anterior tympanotomy operative approach. The results of surgery are reviewed. The possible origins of these localized cholesteatomas are considered. Are they congenital defects that arise from misplaced keratinizing epithelium? Do they arise from mesenchymal cells whose differentiation is stimulated by inflammatory changes within the middle ear?