A New Pathogenesis of Mesotympanic (Congenital) Cholesteatoma

Abstract

Objectives: To introduce a new, acquired pathogenetic theory of mesotympanic cholesteatoma behind an intact eardrum in children and to present some doubts on congenital pathogenesis. Study Design: Literature review. Methods: The incidence and origination of mesotympanic cholesteatoma in children were thoroughly analyzed in the world literature and correlated to the histopathological studies on human middle ear epithelia and to epidemiological studies on secretory otitis, tubal occlusion, and acute suppurative otitis media. Results: The new, acquired theory is based on the fact that that the place of origin of the anterosuperior mesotympanic cholesteatoma is the area of the malleus handle and malleus neck, and of the posterosuperior cholesteatoma, the long process of the incus. During the common pathological conditions there is a great risk of retractions and adhesions of the eardrum to these ossicles. After subsequent loosening of the retracted eardrum some cells of the keratinized squamous epithelium may be left behind and become included into the tympanic cavity, eventually causing an inclusion cholesteatoma. Four basic mechanisms of inclusions are proposed and the presence of great dynamics in middle ear disease in children, with high incidence of tubal dysfunction, retractions, secretory otitis, and acute suppurative otitis, is documented, making the acquired pathogenesis probable. The place of origin does not fit with the congenital pathogenesis of epithelial formation localized on the lateral wall of the eustachian tube close to the annulus. The origination around the malleus and incus fits better with the proposed acquired pathogenesis. Conclusions: There are no definitive proofs for the acquired pathogenesis of the mesotympanic cholesteatoma, nor is there experimental research to prove or disprove it. Key Words:Mesotympanic cholesteatoma, congenital cholesteatoma, acquired pathogenesis of mesotympanic cholesteatoma, cholesteatoma in children, cholesteatoma behind intact eardrum.

The Natural History of Congenital Cholesteatoma

“…Several variations of the invagination theory have been proposed, 12,13 most based on Ruedi's 14 suggestion that otitis media causes an inflammatory injury of the tympanic membrane that invaginates into the middle ear to form a CC. A review of the literature fails to reveal any buttressing histologic or clinical evidence for this postulate.…”

Infantile congenital petrosal cholesteatoma: A case report and literature review

“…Michaels presented another theory in 1986 [9] that congenital cholesteatoma arises from epidermoid cell rests formed before 33 weeks of gestation near the tympanic orifice of eustachian tube. However, the report by Tos in 2000 [10] raised doubts about these previous theories, and thus the pathogenesis of this disease remains controversial.…”

Gegenw�rtige Theorien zur Cholesteatomentstehung

“…Zu ihrer Pathogenese existieren die oben genannten unterschiedlichen Theorien, die teilweise sehr kontrovers diskutiert werden. Während die Mehrzahl der Cholesteatome den letzten vier Theorien zwanglos zugeordnet werden kann, bleibt die Metaplasietheorie umstritten, da sie auch durch neue molekularbiologische Methoden weder bewiesen noch ausgeschlossen werden kann [58,66]. Weiterhin bestehen zusätzliche Möglichkeiten einer ᭤Implanta-tion von Plattenepithel in das Mittelohr.An humanen Felsenbeinstudien konnte gezeigt werden, dass auch ehemalige Retraktionen bei intaktem Trommelfell ᭤Platte-nepithelnester an ihren ehemaligen Anheftungsstellen belassen können (Abb.…”