Wk 4, Case 2 - Review

Patient History
Right ear and jaw pain.

Findings
Pre- and postcontrast MR was performed of the brain and internal auditory canal.

Brain: Sagittal T1-weighted images demonstrate corpus callosum to be intact. No evidence of Chiari malformation. No abnormal pineal region masses. Pituitary gland is not enlarged. Diffusion imaging demonstrates no evidence of recent infarct. Axial FLAIR and T2-weighted images demonstrates marked prominence of the sulci and ventricles. There is increased FLAIR and T2 signal on the ependyma of the lateral ventricles, which is likely due to microvascular angiopathy. No evidence of vasogenic edema or mass effect. Contrast-enhanced T1-weighted images show no abnormal intraaxial or extraaxial enhancing masses.

Skull base: Pre-and postcontrast images were performed through the skull base. The study demonstrates diffuse enhancement of the mucosa of the bony and cartilaginous portions of the right external auditory canal. The abnormal enhancement appears to extend to the expected location of the right tympanic membrane. There is associated diffuse enhancing mucosal thickening involving the right mastoid air cells which extend to the mastoid tip. There is abnormal enhancement involving the right temporomandibular joint suggestive of early phlegmon. In addition, there is increased T2 signal and enhancement involving the right lateral pterygoid muscle at its attachment to the temporomandibular joint capsule. No substantial enhancement is identified involving the right parotid gland. There is no extension of phlegmon into right stylomastoid foramen. No abnormal enhancement is identified of descending portion of right facial nerve. There is evidence of some thinning of the roof of the external auditory canal just lateral to the expected region of the scutum (images 7 and 8 of series 601). No evidence of abnormal dural enhancement or edema involving inferior aspect of right temporal lobe in right middle cranial fossa. CT of the temporal bone can better help evaluate for bony integrity.

Conclusions
1. Abnormal enhancement of the right external auditory canal with findings suggestive of early erosion of the bony roof of external auditory canal. Phlegmon extends inferiorly through floor of external auditory canal (likely via the fissures of Santorini and possibly in combination with a persistent foramen tympanicum [Hushka]) with abnormal enhancement of right temporomandibular joint with associated subtle enhancement and edema of attachment of the lateral pterygoid muscle to the temporomandibular joint capsule. Ipsilateral diffuse enhancing mucosal thickening of right mastoid air cells. Above findings are strongly suspicious for otitis externa with developing skull-base osteomyelitis.
2. No abnormal intraaxial or extraaxial enhancing masses.
3. No evidence of leptomeningeal enhancement or temporal lobe edema adjacent to inflammatory right temporal bone process.
4. No evidence of recent infarct.