An in vitro growth study on cholesteatoma and normal skin.

The ability of cholesteatoma to grow rapidly within the ear is well recognized. This study aimed to quantify the in vitro growth of cholesteatoma derived cells. Following removal of cholesteatoma explant cultures were established. Cellular outgrowths were subcultured and a colony forming assay performed. Cells were repeatedly passaged every 14 days until senescence was observed. In comparison with cells derived from normal scalp skin, cholesteatoma derived cells demonstrated a lower colony forming efficiency in both primary and secondary subcultures, achieved fewer passages and cell generations in serial culture, and achieved a lower total population expansion. No evidence was found to suggest an intrinsic loss of growth control. It is proposed that the majority of cholesteatoma is composed of cells with a limited capacity for growth. Explant studies suggested that these may be the progeny of more highly proliferative cells situated at the neck of the cholesteatoma sac.