Symmetric Bilateral Congenital Middle Ear Cholesteatoma: A Case Report.

Congenital middle ear cholesteatoma (CMEC) accounts for 2%-5% of all cases of middle ear cholesteatoma. CMEC is rare and diagnostically challenging; therefore, only a few cases are reported in the literature, and the pathophysiology of this condition remains largely unclear. Currently, epidermoid formation, amniotic fluid contamination, lack of the tympanic ring, and squamous metaplasia are among the mechanisms implicated in the pathogenesis of CMEC; however, no single theory satisfactorily explains the pathophysiology of this disorder. We report a case of CMEC in a young male patient, who showed a symmetric, binaural whitish mass posterior to the anterosuperior quadrant of the tympanic membrane. A few reports have described bilateral CMEC; however, no study has reported symmetrical CMEC as observed in this case. Bilateral tympanoplasty concomitant with cholesteatoma removal was performed, and histopathological evaluation of the resected specimen showed closed-type cholesteatoma. In this report, we describe a rare case of symmetric CMEC, which supports the epidermoid formation theory associated with CMEC, together with a literature review.