0:00

This is a 58-year-old male with masses

0:03

that are increasing in size, and I want

0:05

to present you with something that is

0:07

interesting, yet is classic to the foot.

0:11

Someone once told me you shouldn't use "classic"

0:14

when you're giving a dissertation, a lecture,

0:16

or teaching, but this one, unfortunately,

0:19

is so classic I have to use the word.

0:22

We have a short axis T1-weighted image

0:25

and a short axis T2-weighted image.

0:28

Within the T2-weighted image, I

0:30

hope you are struck by the striated

0:33

character of the abnormality.

0:36

It looks very complex and serpiginous.

0:39

Perhaps if I put this in the nose, you

0:42

might even call it an inverting papilloma.

0:45

Looks a little bit corduroy looking.

0:47

I'll blow the T1-weighted image up

0:49

as well, but it's not as impressive.

0:53

It is, however, on the T2-weighted image,

0:55

without fat suppression, just as impressive,

0:59

and we have located a second lesion.

1:02

Now, I'm going to put up for you the proton

1:05

density fat suppression image, also known as PD,

1:09

SPIR, SPAIR, SPECIAL, STIR, and demonstrate that

1:14

our lesion, which is predominantly gray, a little

1:18

bit lighter than muscle, but not much, is more

1:21

hyperintense on this sequence because it does

1:24

have some water in it, but not a lot of cytoplasm.

1:28

So the fact that it's bright on the water-weighted

1:32

fat-suppressed image should in no way take you

1:36

out of the realm of fibrous lesions or tumors.

1:39

Because virtually everything

1:40

is going to be bright here.

1:42

And the purpose of this sequence

1:44

is detection, not characterization.

1:48

So let's go back to our detection sequence.

1:51

Let's put up our long axis coronal.

1:54

And the reason I started with

1:56

short axis was not purely random.

2:00

It was because when I am dealing with a mass in

2:02

any part of the body, I want to have a short axis

2:05

view because that's where my comfort zone is.

2:08

from years and years and years of axial CT.

2:11

And I'll bet that's where

2:12

your comfort level is, too.

2:13

So I'm just trying to help you

2:14

get more efficient and faster.

2:17

The long axis view looks

2:18

more like an AP projection.

2:20

That, too, is pretty comfortable.

2:23

Let's for a moment just take a look at the

2:25

sagittal view, which is like a lateral view on

2:28

a radiograph, and we'll again see these lesions.

2:33

Now, if I were to give you the

2:34

diagnosis, typically these lesions

2:35

occur a bit more proximally.

2:38

So there's some atypicality to this case.

2:41

Which means you have to think carefully

2:44

about other diagnostic considerations

2:47

and the family of fibrous lesions in the foot.

2:50

The typical fibrous lesion is

2:53

non-aggressive fibromatosis, also known as

2:56

Ledderhose's disease, similar, identically,

3:01

to Dupuytren's contracture of the hand.

3:05

Now histologically they look the same,

3:07

but they behave somewhat differently, and

3:10

there is an association between the two.

3:12

People that get Dupuytren's

3:14

get fibromatosis of the foot and vice versa.

3:17

But the ones in the feet tend to be thicker

3:19

and they're more likely to be nodular.

3:23

There are a whole family of benign

3:26

and aggressive fibromatous lesions.

3:28

An entity called deep fibromatosis is sometimes

3:32

used as a synonym for aggressive fibromatosis.

3:37

And you'll hear aggressive fibromatosis sometimes

3:40

used as a synonym for patients who have desmoids.

3:45

On the other hand, this condition is

3:48

known as superficial fibromatosis.

3:50

What makes it confusing is sometimes

3:53

it can grow into deeper spaces.

3:56

So you might have deep growth of this condition,

4:00

superficial fibromatosis, Ledderhose's disease,

4:04

which is not some rare bird, by the way.

4:06

It's extremely common.

4:08

It just happens to occur more proximally.

4:10

It just happens to occur more medially.

4:13

And this one is atypical because it

4:15

occurs more laterally and more distally.

4:18

You would have to consider, strongly,

4:21

other fibroblastic conditions, such

4:24

as a desmoid, and things like nodular

4:29

fasciitis, and pseudosarcomatous

4:31

fasciitis, and even fibrosarcoma.

4:35

But fibrosarcomas tend to be not as whorl-

4:38

like as desmoids, nor as this condition.

4:42

This condition of plantar fibromatosis, the deeper

4:46

it grows, the harder it is to get rid of it.

4:49

In fact, if you excise it, it comes back more than

4:52

50 percent of the time, even when it's small.

4:56

If the signal intensity is brighter than

4:59

muscle, then it has a higher likelihood

5:03

of intense cellularity, and that also

5:07

produces increased risk of recurrence.

5:10

So those are two things you should pay

5:11

careful attention to, along with the

5:13

spaces of involvement, especially if a

5:16

surgical excision is being contemplated.

5:19

And when would you contemplate that?

5:21

Intractable pain.

5:23

Otherwise, these are typically left alone.

5:26

Plantar fibromatosis, a typical location,

5:30

whorl-like appearance simulating a desmoid.

5:34

It's atypical because it's

5:35

lateral instead of medial.

5:36

It's atypical because it's

5:38

more distal than proximal.

5:39

It usually occurs closer to the first toe.

5:43

These do not metastasize.

5:45

These fall into the family of

5:48

fibromatoses, which can be divided up into deep

5:51

and superficial, or aggressive and non-aggressive.

5:54

125 00:05:54,350 --> 00:05:55,620 And you can read more about

5:55

them on MRI Online.