Introduction: Congenital cholesteatoma (CC) of the middle ear is a rare clinical entity that classically presents as a white mass situated in the anterior-superior quadrant of the middle ear behind an intact tympanic membrane (TM). Derlacki and Clemis established the diagnostic criteria for CC: 1) A pearly white mass medial to an intact TM, 2) Normal Pars Tensa and Pars Flaccida, 3) No history of otorrhea, perforation or previous otologic procedures. CC is seen far more frequently in children, but House and Sheehy remarked adult patients with cholesteatoma behind an intact TM.

Materials and Methods: A retrospective analysis was conducted of the clinical charts of all patients with CC in both children (n = 56) and adults (n = 6) from 1992 to 2015. CCs of the petrous apex (n = 15) were excluded. 1445 cases of acquired and congenital cholesteatomas were treated, therefore, the prevalence of CC should be 4.3% (62/1445).

Results: Based on the staging system by Potsic 54 patients were classified into stage1–4 according to the surgical findings: 11 cases in stage1, 7 in stage 2, 24 in stage3, and 20 in stage4. It was suggested that most CCs could be derived from the epidermoid formation (EF) in 53 cases. A planned two-staged surgery was conducted in 54 cases (87%), while one-stage surgery was adopted in 8 cases. The residual cholesteatoma at the time of second stage surgery was detected in 19 out of 48 cases (40%). The most common residual sites were at oval window (n = 7). Hearing assessment was done in 55 cases: success in 46 cases (84%), moderate in 8 cases, and failure in one.

Discussion: As the stage of CC advanced, the area of its invasion could be enlarged, which should result in a higher risk of CC residual. Considering that CC is usually discovered in its advanced stages (stage 3–4), the establishment of a screening program including otoscopic and CT examinations and hearing tests for early CC diagnosis should be required.