Middle ear congenital cholesteatoma: systematic review, meta-analysis and insights on its pathogenesis

Purpose: Congenital cholesteatoma (CC) presents as a white pearl-like lesion behind a normal tympanic membrane (TM), without a history of otorrhea, infection, perforation or previous otologic surgery. Several recent studies provided new data improving this pathology characterization. The aim of this paper is to expand the knowledge about CC and to provide new insights on its pathogenesis. Methods: The study consisted of two main research parts: (1) systematic review and meta-analysis; (2) medical literature review englobing anatomy, histology, embryology and congenital pathology of the ear. Results: The search strategy identified a total of 636 papers. Seventy retrospective studies were included. A total of 1497 cases were studied and the mean age was 6.58 years, with a male–female ratio of 3:1, 34% were asymptomatic, 26% had hearing loss and 2% had facial dysfunction/paralysis. The overall estimate for antero-superior quadrant involvement was 0.70 [95% confident interval (CI) 0.64–0.76], in the postero-superior quadrant was 0.60 (95% CI 0.52–0.69), in the antero-inferior quadrant was 0.32 (95% CI 0.23–0.41), in the postero-inferior quadrant was 0.38 (95% CI 0.29–0.47), in the attic was 0.53 (95% CI 0.43–0.63) and in the mastoid was 0.33 (95% CI 0.26–0.41). More advanced Potsic stages were present in older patients. The most likely inclusion place seems to be between the pars flaccida and the upper quadrants of the pars tensa. Conclusions: During the last decades, a substantial improvement in CC diagnosis and management had been achieved. The presented mechanism seems to explain most of middle ear CC.