PMC3426184_01
Audiogram showing right mild to moderate conductive hearing loss with air bone gab, accounting from 40 to 60 dB loss and normal left hearing level.
CRIM.OTOLARYNGOLOGY2012-548340.001.jpg
PMC3426184_01_CRIM.OTOLARYNGOLOGY2012-548340.001.jpg
fig1
Audiogram showed right moderate conductive hearing loss (CHL) (Figure 1) with shallow type-A tympanogram. 
Computed tomography: coronal image, bone window (a) and soft tissue window with contrast (b and c) showing sclerotic contracted right mastoid temporal bone with most mastoid air cells being occupied by polypoidal expansile soft tissue densification lesion (heterogeneous, nonenhanced in contrasted soft tissue window image).
CRIM.OTOLARYNGOLOGY2012-548340.002.jpg
PMC3426184_01_CRIM.OTOLARYNGOLOGY2012-548340.002.jpg
fig2
Computed tomography (CT) of the temporal bone (Figure 2) showed right mastoid and middle ear mass with intracranial extradural extension elevating the right temporal lobe of the brain.
Axial T2-WI (a), coronal T2WI (b), axial T1-Gd (c), and coronal T1-Gd (d) showing a large expansile extraaxial right mastoid mass causing elevation of the right temporal lobe demonstrate heterogeneous signal intensity on T2 and minimal enhancement in post contrast.
CRIM.OTOLARYNGOLOGY2012-548340.003.jpg
PMC3426184_01_CRIM.OTOLARYNGOLOGY2012-548340.003.jpg
fig3
Magnetic resonance imaging (MRI) of the temporal bone and brain with and without gadolinium (Figure 3) revealed T1 and T2 sequences of heterogeneous but predominantly hyperintense mass located mainly in the right mastoid and middle ear cavity causing elevation of the right temporal lobe of the brain.
(a) Hematoxylin and Eosin stain (x100 magnification) section showing histology of a dermoid cyst. The cyst is filled with keratinous material in the lumen and is lined by stratified squamous epithelium that is responsible for the synthesis of luminal keratin. The tissue underlying the squamous lining comprises pilosebaceous units (b).
CRIM.OTOLARYNGOLOGY2012-548340.004.jpg
PMC3426184_01_CRIM.OTOLARYNGOLOGY2012-548340.004.jpg
fig4
Histopathological report (Figure 4) showed dermoid cyst.
Three months after surgery, the CT (a, b) and MRI (c, d) of the temporal bone and brain revealed complete resection of the dermoid cyst and return of the right temporal lobe of brain to its normal position.
CRIM.OTOLARYNGOLOGY2012-548340.005.jpg
PMC3426184_01_CRIM.OTOLARYNGOLOGY2012-548340.005.jpg
fig5
Three months later, the CT with and without contrast and MRI with and without gadolinium of the temporal bone and brain (Figure 5) revealed complete resection of the dermoid cyst and return of the right temporal lobe of the brain to its normal position.