Learning Objectives: In this paper we present a study in which cytokeratins have been used to characterize congenital cholesteatoma and epidermoid (and we compared these patterns with previous data on acquired cholesteatoma and ear canal skin) in order to confirm or invalidate a developmental theory.
Introduction: Histologically ear canal skin, epidermoid, congenital and acquired cholesteatoma are indistinguishable. They all contain keratin, a matrix of keratinizing stratified squamous epithelium and a lamina propria-perimatrix. Nowadays still different theories on the development of congenital cholesteatoma and epidermoid are suggested.
Cytokeratins are intermediate filament proteins that are exclusively present in epithelial cells and can be used to study epithelial differentiation.
In this paper we present a study in which cytokeratins have been used to characterize congenital cholesteatoma and epidermoid (and we compared these patterns with previous data on acquired cholesteatoma and ear canal skin) in order to confirm or invalidate a developmental theory.
Methods: Cytokeratin Antibodies RCK103, RCK105, M20, CK18–2, LP2 K, AE14, RCK107, E3, KA12, LL025, RKSE60, 6B10 en 1C7 were used to characterize the cytokeratin pattern of congenital cholesteatoma and epidermoid of the cerebellopontine angle. These data were compared with previous patterns on acquired cholesteatoma and medial and lateral ear canal skin.
Results: Our results show that the cytokeratin pattern of congenital cholesteatoma and epidermoid differs. The cytokeratin expression of congenital cholesteatoma mimics the pattern of acquired cholesteatoma and medial ear canal skin: slightly positive LP2 K (Ck19), AE14 (Ck5), 6B10)Ck10) and 1C7 (Ck13). The pattern of epidermoid is comparable to that of normal skin: negative LP2 K, 6B10 and 1C7 and positive AE14.
Conclusions: The cytokeratin pattern of congenital cholesteatoma, acquired cholesteatoma and medial ear canal skin coincide. This may support the invasion theory as explanation of its development. Epidermoid and lateral ear canal skin share the same cytokeratin pattern which may support the ectodermal rest theory.
