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Dr. P here. I want to talk to you a little bit about kids.

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3 00:00:04,300 --> 00:00:06,029 Um, this is a patient under 10 years

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of age, and unfortunately, the child has

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neuroblastoma on a prior CT, which I have on

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the left-hand side from 5 to 6 years earlier.

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And then in the middle, I have an axial T2

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from 2017, and then an axial T1 appearing GRE.

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Now, I'd like to talk a little bit about, uh,

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cysts for a moment, because this child does

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have a, quote unquote, lesion in the right

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kidney, and I think you can see it right here.

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Now, by definition, a simple cyst in a child or an

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infant occurs in a kidney with an otherwise normal

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renal parenchyma and a normal contralateral kidney.

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It's round, it's thin-walled, it's anechoic,

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it's non-septated, and it's separate from the

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collecting system, and it has, importantly,

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no Doppler blood flow related to the cyst.

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Now, you all know there's no Doppler on MRI,

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even though this is MRI online, and that's

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because ultrasound is the modality of choice to

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evaluate cysts in young children and neonates.

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Cysts with additional features like solid

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components, septations, thick walls,

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those should be considered complex cysts.

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Now, another point relevant

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to this case, if the patient has a

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background of underlying systemic disease.

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Uh, that you have to also take into

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consideration when you're making this, uh,

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decision as to whether to go further with

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something that is more complex like CT or MRI.

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A differential diagnosis, uh, includes the

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first manifestation of other cystic diseases,

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chaliceal diverticula, hydrocalyx, cystic

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dysplasia, and very rarely hydatid cyst.

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So, in other words, a cyst in a young patient can be

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the first manifestation of one of the heredofamilial or

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other cystic syndromes that you might find in children.

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Post-traumatic kidney cysts have

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been described mainly in adults.

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I personally have never seen a

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post-traumatic cyst in a child.

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A couple of other take-home points.

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A child with a first-time diagnosis of a single kidney

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cyst requires a detailed medical and family history.

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And a thorough examination of at

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least one follow-up assessment.

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Because, frankly, simple kidney

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cysts are rare in children.

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And they, again, may be the first manifestation

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of a cystic disorder or genetic cystic disease.

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So, let's keep that in mind.

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This child has neuroblastoma, and

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that's why we went to the doctor

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to an MRI to find this lesion, which

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was, by the way, detected at ultrasound,

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was not uniformly simple and round.

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It had some complex internal character to it.

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Here it is on the T2 weighted image.

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Let's scroll it a little bit.

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And then here it is on the T1 GRE, and it is not dark,

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like you would expect water to be, like the CSF fluid.

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So, we're dealing with something else other than

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a simple cyst, thus the reason to move forward.

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And by the way, the CT shows

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absolutely, positively nothing.

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Let's move on, shall we?

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Dr. P out.