NEUROFIBROMA OF THE FACIAL NERVE IN THE FACIAL CANAL: Destruction of the Labyrinth and Mastoid Process

Abstract
The case of neurofibroma of the seventh nerve reported here is of interest not only because it is apparently the first instance of neurofibroma of the facial nerve involving the mastoid bone to be reported but also because it illustrates the procedure which seems most logical to follow when in the presence of a destructive process involving the mastoid bone a diagnosis of a malignant process cannot be made without performing an exploratory operation. A malignant lesion of the mastoid bone is usually secondary to carcinomatous degeneration of squamous epithelium of the aural canal or of squamous epithelium which has invaded the cavity of the ear or the mastoid antrum during the reparative process following a destructive type of acute otitis media. The occurrence of a primary malignant process in the mastoid bone is exceedingly rare, Lillie1having reported the only proved case that was encountered at the Mayo Clinic