抄録
A case of Labyrinthitis ossificans in the presence of chronic suppurative otitis media with cholesteatoma diagnosed with CT and MRI was presented.
The patient was a 44-year-old female, whose left middle ear was filled with cholesteatoma. Her left inner ear showed complete loss of functions, but we couldn't decide it to be congenital or acquired . CT and MRI of the inner ear revealed blurring of the cochlea with ossification in the lower part of the basal turn, and abscence of the vestibule.
First, we had thought these abnormal inner ear findings to be due to congenital anomaly, but we reviewed the case postoperatively. 1) In cases of severe inner ear anomaly, hypoplastic temporal bones and narrow internal auditory canals usually are present, but these findings were absent in this case. 2) Compared with the abnormality of the cochlea, that of the vestibule was too severe to interprete the case as anomaly. 3) Arcuate eminence was thought to be present. 4) Abnormality of the cochlea was in the lower part of the basal turn instead of the apical turn as is usually seen in anomaly. These supported the opinion that this was a case of labyrinthitis ossificans rather than anomaly. In this case, cholesteatoma was supposed to have destroyed the lateral semicircular canal first and caused localized labyrinthitis in the vestibule leading to inner ear ossification.
Great care should be taken in diagnosing radiological inner ear abnormality particularly in the presence of chronic otitis media, because in some cases of labyrinthitis ossificans as in this case, differentiation from inner ear anomaly may be very difficult.
