Histopathologic Characteristics of Internal Auditory Canal Diverticula.

Area of Science:

• Otolaryngology
• Histopathology
• Auditory Neuroscience

Background:

• Internal auditory canal (IAC) diverticula have been observed histologically with cavitary otosclerosis.
• Recent imaging studies suggest a higher prevalence of IAC diverticula than explained by otosclerosis alone.

Purpose of the Study:

• To investigate whether internal auditory canal (IAC) diverticula occur independently of otosclerosis.
• To correlate the presence of IAC diverticula with hearing thresholds in temporal bone samples.

Main Methods:

• Examination of hematoxylin and eosin stained temporal bone histopathology slides.
• Inclusion of temporal bones from individuals over 18 years old with and without otosclerosis.
• Evaluation of IAC diverticula in normal hearing subjects and those with otosclerosis.

Main Results:

• IAC diverticula were identified in 70% of temporal bones with otosclerosis and 25% of normal temporal bones.
• No statistically significant difference in mean pure tone averages (PTA) was found between normal temporal bones with and without diverticula.

Conclusions:

• Internal auditory canal (IAC) diverticula can manifest independently of otosclerosis.
• Individuals with IAC diverticula and no other temporal bone pathology exhibit normal hearing thresholds.