The incidence of otosclerosis in Japanese is low and only a few authors have reported temporal bone findings in otosclerosis.
In our experience, six surgically acquired specimens from ears with typical audiometric characteristics of stapes fixation revealed foci which belonged to a classification of a true otosclerosis.
The specimens showed all stages of otosclerotic maturation:
i) osteoclastic destruction and osteoblastic activities around the newly forming bone.
ii) osteoid blue bone with osteoblasts, forming the “blue mantle”.
iii) acidphilic remodeling bone with osteoblasts.
iv) highly mineralized acidphilic bones with a mosaic-like appearance.
In most of stapes fixation in tissues from Japanese patients, the same otosclerosis as is seen in Caucasians was evident.