外耳道真珠腫

抄録

Japanese and foreign literature concerning cholesteatoma of the external auditory canal is reviewed.
Between two major theories on the etiology of cholesteatoma of the external auditory canal, one that supports the origin in the external auditory canal per se has been more widely accepted than the other that seeks the origin in the middle ear. Pathology of this disease includes ; 1) intact tympanic membrane or the one with occasional thinning, 2) hyperkeratinization in the bony protion of the exteranal auditory canal and 3) occasional bony destruction in the external auditory canal.
Among many theories on the developmental mechanism the disturbance of normal migration of the epithelium of the tympanic membrane and the external auditory canal due to various reasons, such as local inflammation or morphological abnormalities, with eventual accumulation of debris and bony destruction appears most plausible for the explanation of the pathology.