Cholesteatoma: spontaneous occurrence in the Mongolian gerbil Meriones unguiculatis.

Spontaneous aural cholesteatomas were found in thirty-two of seventy ears (45.7 percent) of adult Mongolian gerbils, Meriones unguiculatis. These cholesteatomas arise from the tympanic membrane and the medial ear canal. The advancing front of these cholesteatomas is histologically identical to that of human cholesteatomas. Since the gerbilline cholesteatoma erodes bone and invades the labyrinth and the cranial cavity, it provides an animal model with which to study the destructive properties of human cholesteatoma.