0:00

This was a patient who had decreased sensation along

0:05

the anterior aspect of the face below the orbit.

0:09

Scrolling the axial scans,

0:12

one sees a mass in the floor of the orbit.

0:18

It is well-defined and quite round

0:21

without infiltrative margins.

0:26

Looking on the coronal scan,

0:29

we can see that this lesion is intimately associated

0:33

with the infraorbital foramen.

0:37

The normal infraorbital foramen

0:39

is seen on the left side.

0:41

On the right side,

0:42

we see depression of the infraorbital foramen,

0:45

and we see the mass, which is extraconal in location.

0:50

We see that it is displacing the inferior rectus

0:54

muscle upward. Here's our medial rectus muscle,

0:57

our superior oblique,

0:59

our superior rectus muscle, and our lateral rectus muscle,

1:03

with the optic nerve sheath complex centrally located.

1:07

So this is indeed an extraconal mass.

1:10

When one considers extraconal masses that are well

1:13

defined, one should consider schwannomas.

1:17

Now, these schwannomas may be involving the portions of the

1:22

cranial nerves that innervate the extraocular muscles,

1:26

or it could be a branch of the fifth cranial nerve.

1:30

We know that the infraorbital nerve is a branch of

1:34

the second division of the fifth cranial nerve,

1:37

also known as the maxillary nerve.

1:39

So in looking at this case and noting that it was

1:43

extraconal, involving the infraorbital foramen,

1:50

I went strongly for a schwannoma of the infraorbital

1:53

nerve, a branch of the maxillary nerve.

2:00

What I failed to understand was that this patient

2:03

had previously had an orbital floor fracture.

2:07

This ended up, histopathologically, being a giant cell

2:11

reparative granuloma, associated with the orbital floor

2:15

fracture and the trauma and hematoma that was

2:19

associated with it many years earlier.

2:22

This was a very tricky case.