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Dr. P back with our five-year-old Wilms tumor patient

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3 00:00:03,630 --> 00:00:06,910 and Wilms tumor at gross inspection is typically a

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well-circumscribed or macro-lobulated lesion.

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But I want to illustrate a couple of things here.

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On my sagittal T2 on the far right, I've got a

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little bit of central hyperintense necrosis.

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These lesions also bleed,

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which we've demonstrated previously.

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In the middle, we've got a T2 spin echo with a

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moderate to longish T, about 1500, and a T, about 225.

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So, low signal on the GRE and

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low on the T2 weighted image.

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But the large area of hemorrhage is

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demonstrated as the circumferential area right here.

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And we showed you a large

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subcapsular hemorrhage previously.

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So, this lesion was associated with a lot of blood.

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We showed you calcium before.

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And we're also showing you now, on the

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sagittal T2, an area of central necrosis.

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So let's talk a little bit about what happens

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in Wilm's tumor histologically and biochemically

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that allows this soup of calcium 15%

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of the time, necrosis, hemorrhage, and so on.

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Wilm's tumor histology has a triphasic

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appearance, which consists of stromal, epithelial

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and blastemal elements that basically,

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recapitulates the development of the normal kidney.

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Now, not all tumors are triphasic.

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You get biphasic and monophasic Wilms tumors too.

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And tumors that consist of only one

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blastemal element resemble other small

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round cell tumors like neuroblastoma.

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And that's why location and identifying

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normal adrenal glands is so important.

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Now sometimes you'll even hear the term

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teratoid Wilms tumor, applied if there's differentiation

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along tissue lines not normally found in

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the kidney, such as muscle, osteoid, which

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may simulate the ORTI tumor or cartilage.

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Fat we said may be detected, but you get fat in

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renal cell carcinoma, you get fat in angiomyolipoma.

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Now, 10% of Wilms tumors show

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anaplastic histology, which is,

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is considered an unfavorable prognosis.

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And these tumors often have a very mixed

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pattern of all these things we've described

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with some really exuberant necrosis.

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Let's move on, shall we?

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Dr. P out.