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Dr. P here with a 61-year-old woman who's reported

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3 00:00:04,860 --> 00:00:09,500 for approximately six months that she has a

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mass growing in her foot, acquired an MRI with

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an axial or short axis T2 showing the mass

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with a little bit of high signal inside it.

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And if we scroll it a little bit, there's also

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some low signal in the middle of it as well.

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The T1-weighted image adds little other than

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furthering the anatomic construct of the

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lesion, showing how it spreads the toes and

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follows the course of the interdigital space.

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Another important finding on all three

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images, by the way, is the fact that it's

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pooching out the plantar space into the

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subcutaneous region, which by the way was

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a site where a biopsy went, so that's a bit

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unsettling that is growing out the biopsy site.

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And here in the axial T1 C+, this is C-,

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this is C+, it is avidly enhancing with some areas

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of perhaps necrosis that are not enhancing.

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So that produces an approach to

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this case, what are you going to do?

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You've got this giant thing

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in the foot of an adult woman.

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How do you handle a case like this?

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First zone of transition,

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not so good at the site where they biopsy.

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Second, internal architecture, very homogeneous.

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Some of the architecture is a little bit

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radial, a little bit is septated.

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There is some central necrosis.

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There is some dark signal inside.

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Maybe that's blood, maybe that's

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fibrous tissue as part of the tumor.

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We know that synovial sarcoma likes the foot.

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If we think about foot-loving

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large masses, that would be one.

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You can get MFHs, malignant fibrous histiocytomas,

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in the foot or myxofibrosarcs of the foot.

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They tend to like the thigh.

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Another lesion that really likes the foot

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is plantar fibromatosis, and they can

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get huge, but this isn't arising from the

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plantar fascia, nor does it have that very

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crisp, collagenous, spoke-wheel, laminar

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appearance of a desmoid-like lesions.

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So, we're kind of stuck right here,

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and if we go to, say, something that is long axis,

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let's take this one right here,

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the long-axis T2, you get the hint

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that there's a little point, like it

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was hanging from a tree and there was

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a branch attached to it right there.

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And maybe it's tapering a

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little bit here, not so much.

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But it certainly is tapering there.

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And it's splaying the two toes apart.

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So at least you have to think about

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potentially, that this arose from the

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digital nerve, or one of the digital nerves.

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And in terms of your job, your job

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is to say, is it a neoplasm or not?

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And the answer is, it's a neoplasm.

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B, is it vascular?

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Yes, it's vascular.

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C, does it cross boundaries?

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Well, after the biopsy,

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yes, it crosses boundaries.

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D, how big is it?

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That's very straightforward.

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E, zone of transition.

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We've got that.

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And it has a pretty good zone of

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transition through the majority of it.

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Is it calcified?

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That's hard to tell.

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You might need an x-ray to

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make that determination.

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And then finally, do you think

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it's aggressive, malignant or not?

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And I use the term aggressive.

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versus non-aggressive.

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And I think this one is indeterminate trending

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towards more aggressive because it's grown out the

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blowhole of where they stuck the needle in there.

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So we certainly have a problem.

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Now, another diagnosis that you'd want to consider

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here is a neural tumor, especially a neurofibrosarc.

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They can occur isolated without NF1.

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And the fact that you have this little

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nipple right here that looks like

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it's going into the interdigital space.

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And the signal is good for neurofibrosarcoma.

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This central heterogeneous high and low signal

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in the middle of the mass is also consistent

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with the diagnosis of neurofibrosarcoma.

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And it's a little bit organized for synovial

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sarcoma in terms of its internal architecture.

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And I'll show you what I mean by that

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when I show you a synovial sarcoma.

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So I would have put that down a little lower.

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Our team did opt for a neural tumor of

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intermediate or more aggressive character,

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and it turns out to be a neural tumor.

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We never got back whether it was

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malignant or benign, but I suspect

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This is one of moderate aggressiveness.

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It's probably a neurofibrosarcoma.

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It is a proven neural tumor of neural origin.

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The only other thing I want to share

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with you is the gradient echo, which is

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somewhat useless, except for one thing.

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It would show calcification,

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and it would show hemosiderin

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hmorrhage, or any kind of hemorrhage within.

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So the fact that we have this is very nice,

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we don't have to do the CT, it is a non-calcified,

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non-hemorrhagic mass, and it is proven.

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Dr. P out.