Congenital cholesteatoma of the middle ear: occurrence of an "open" lesion.

Objective: This study aimed to investigate the occurrence of an "open" form of congenital cholesteatoma to facilitate better understanding of the different histopathologic forms and their differing clinical presentations.
Study Design: Retrospective case review.
Setting: Tertiary referral center.
Patients: Ten patients diagnosed with congenital cholesteatoma, that is, a white "pearl" behind an intact tympanic membrane with no history of trauma, ear surgery, perforation, or otorrhea.
Main Outcome Measures: Audiometry, high-resolution computed tomography scan of the temporal bones and intraoperative findings.
Results: Two of 10 patients had lesions located in the anterosuperior quadrant of the mesotympanum. Four patients had lesions involving the entire middle ear cleft. Four patients had lesions in the posterosuperior quadrant. Seven of the patients were found to have a typical "closed" cyst, whereas the remaining three patients showed an open cholesteatoma matrix.
Conclusions: Apparently, there are two types of congenital middle ear cholesteatoma: a closed keratotic cyst and an open matrix. Patients with open cholesteatomas may have a clinical presentation that is uniquely different from the classical description of congenital cholesteatoma.