0:00

This is another child who had leukocoria,

0:04

absence of the red pupillary reflex.

0:07

In this case, the leukocoria was on the right side.

0:11

This is a T2-weighted standard imaging sequence

0:15

through the orbits. As we scroll through,

0:18

we see the clear abnormality on the right side with

0:24

intermediate signal intensity, replacing the bright

0:26

signal intensity of the vitreous humor.

0:29

Again, we see an irregular mass

0:32

which is projecting into the vitreous humor,

0:35

and which courses along the posterior

0:37

aspect of the globe.

0:40

We also see an elliptical area

0:45

which ends at approximately 2 o'clock on the globe.

0:50

A priori, we would say that this is most likely representing

0:53

a retinal detachment associated with this mass.

0:57

The next most important thing that you would do

1:00

in evaluating a patient who has an ocular mass,

1:04

is to check the age of the patient.

1:07

If this is a child,

1:08

the most likely diagnosis, far and away, is retinoblastoma.

1:13

If this is an adult,

1:14

the most likely diagnosis, far and away, is ocular melanoma.

1:19

And the ocular melanomas arise from the choroid, whereas

1:24

retinal blastomas arise from the retina.

1:27

Let's scroll through this case

1:30

and see the extent of the lesion.

1:34

Here we have a nice view of the optic nerve

1:37

sheath complex, bilaterally.

1:38

In this case,

1:40

the CSF around the optic nerve is seen as the bright signal

1:43

intensity on the T2-weighted scan, with the optic nerve

1:47

inserting into the globe, and we see this well

1:50

on the contralateral side.

1:52

Let's continue to scroll and we note that there is no

1:56

abnormality at the level of the optic chiasm or intracraniall.

2:03

The next sequence to look at is the post-gadolinium

2:06

enhanced fat-suppressed sequence.

2:09

As you can see,

2:11

this patient's abnormality shows contrast enhancement.

2:14

We are seeing

2:17

the enhancing tumor,

2:21

which shows less enhancement than the brighter

2:25

signal intensity of the retinal detachment.

2:29

Let's continue to scroll and make sure that the

2:32

optic nerve sheath complex is not involved.

2:36

Here we have the optic nerve well seen with no evidence of

2:41

enhancement along the optic nerve, nor in the optic canal,

2:45

and nothing superiorly along the optic chiasm.

2:52

Are we done with this case?

2:56

Let's go back and look at the high-resolution imaging.

3:02

For those of you with sharper eyes,

3:04

you may have noticed that there was abnormal signal

3:09

intensity in the contralateral globe.

3:15

Here we see abnormal thickening and nodularity

3:20

along the left globe.

3:23

And in fact, if we go back to the non-high-resolution imaging,

3:29

you see the same.

3:33

Abnormality in the contralateral globe.

3:36

This is very important to make the diagnosis, because small

3:41

retinoblastomas may escape ophthalmologic detection.

3:48

If one has bilateral retinoblastomas,

3:52

you have to alter the potential therapy

3:55

because we cannot do bilateral enucleation of a child,

4:00

and expect the child to go through school properly.

4:05

So at this juncture,

4:06

the clinicians have to make a decision about what to

4:09

do about a patient who has a tumor in both eyes.

4:12

Because the therapy includes brachytherapy, sclerotherapy,

4:18

laser ablation, enucleation,

4:21

and other potential chemotherapy.

4:25

In this situation,

4:27

what generally happens is that the patient who has a tumor,

4:31

involving greater than one-third to one-half the volume of the globe,

4:36

has enucleation because of the lack of response to radiation therapy,

4:41

and chemotherapy with large retinoblastomas.

4:44

The contralateral tumor, however, that is smaller in size,

4:49

would be treated with those non-enucleative therapies.

4:55

The final comment to make about retinoblastoma is that

5:00

the retinoblastoma gene also increases the risk of sarcomas.

5:07

Those sarcomas may occur throughout the body.

5:12

However, they have a predilection for the head and neck region.

5:15

And in particular,

5:16

if a patient is treated with radiation therapy,

5:20

the sarcoma possibility increases dramatically.

5:25

So, you have the genetic predisposition of the retinoblastoma

5:30

gene, and you have radiation therapy,

5:34

which has a possibility for causing a neoplasm.

5:37

These sarcomas usually occur in later childhood than the

5:43

retinoblastomas, which occur 90% of the time before age two.

5:48

So, we want to look at the additional soft tissues of the

5:54

head and neck to make sure that we don't see sarcomas.

5:58

These sarcomas may be involving the muscle or the bone.

6:04

In this case,

6:05

although the patient had bilateral retinoblastomas,

6:08

and therefore, the hereditary form of retinoblastoma,

6:11

there were no sarcomas identified.