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This was a 20-year-old patient who had a fleshy mass

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that was identified in the right external auditory

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canal which had been growing over time.

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I'm showing you the T2-weighted scan and the

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post-gad T1 fat-suppressed scan from a

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skull-based study of this patient.

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On the right side, we see a lesion which on the T2

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weighted scan has heterogeneous signal intensity.

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It almost has a striped appearance as you look at

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the cartilaginous portion of the external

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auditory canal and its anterior wall.

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But going a little bit more medially, we see again

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somewhat heterogeneous low signal intensity mass

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that infiltrates the external auditory canal and

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appears to extend to the temporomandibular joint

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on the right side with a little

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bit of a tongue of tissue.

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This is a very unusual shape to this lesion and it's

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kind of curious as far as the signal intensity with

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the darker areas on the T2-weighted scan.

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On the T1 post-gadolinium enhanced scan, we see

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that this mass pretty much uniformly enhances.

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There is the residual external auditory canal that

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we're seeing just partial volume average here on the

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post-gad image, but there is also involvement on

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post-gad of what appears to be the

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dural surface of the temporal bone.

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So given the intermediate to

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low signal intensity on the

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T2-weighted scan and the enhancement pattern which

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kind of looked like there may even be a dural tail,

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we were in the realm of the possibility

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of an extracranial meningioma.

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Here is the coronal image showing that very avid

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contrast enhancement and what we thought was a

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little bit of a dural tail coming

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along the edge of the lesion

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at the temporal bone and extending extraosseously.

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So a difficult case. And in this case,

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if we look back at the T2-weighted scan, it has a

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feature that has been described with neurofibromas,

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and that is that you almost have a target-like

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appearance to it with areas of bright signal

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intensity and dark signal intensity around

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the periphery of the lesion.

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This may be better demonstrated on the sagittal T2

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weighted reconstruction from the cyst image

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in looking at this lesion. So, very heterogeneous,

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you may suggest that there are some dark and bright area, centrally,

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this may represent the Antoni A and Antoni B

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tissue of a neurogenic tumor.

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So the final diagnosis here was a neurofibroma,

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an unusual lesion, and again,

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not something that is typically seen in the external

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auditory canal. Had the patient have a history of,

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for example, neurofibromatosis type 1,

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we might have gone that route.