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So, most of you know that I really

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enjoy neurenteric cysts.

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The reason why I enjoy neurenteric cysts is because

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they, too, may be intradural or extradural,

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and they may be intramedullary or extramedullary,

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but they have a characteristic feature that

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would lead to a specific diagnosis.

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So these are, again,

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developmental abnormalities with a persistence in

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the connection between the central

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nervous system and the GI system.

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So, that's why it's called neurenteric.

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And the imaging feature,

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as you see in these two different patients with

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neurenteric cysts that gives away the diagnosis,

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is the vertebral body segmentation anomaly?

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Neurenteric cysts are associated with the peculiar

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appearance of the bone. In this case,

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you see kind of a fused bone that is a little

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bit too large for a normal vertebra.

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However, they may be associated with butterfly vertebra,

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or hemivertebra, or as you see here,

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with congenitally fused vertebrae.

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The cysts may have high protein associated

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with them, so they may be bright or dark.

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In this case, we have one.

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This is actually a proton density-weighted scan,

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so it's brighter than CSF.

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This one also on a T2-weighted scan,

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almost seems brighter than the CSF.

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And as you can see,

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there is a little meniscus here identifying it as a

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intradural extramedullary lesion, displacing the

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spinal cord posteriorly. However, neurenteric cysts,

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as I said, can extend intramedullary,

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and they can extend into the extradural space.

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They may also be associated with a bronchial cyst or

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a gastroenteric cyst at the same level or

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at other levels above or below.

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Rarely, they may be associated with

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spinal dysraphic states,

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and it may be a source of myelopathy

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or radiculopathy.

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So this is my favorite case of all time,

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which I believe I've demonstrated when I was

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talking about the intradural intramedullary lesion.

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Why is it my favorite case of all time?

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Well, it's a young adult who has a neurenteric cyst and

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this neurenteric cyst shows elements

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of being intradural extramedullary,

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intradural intramedullary, as well as extradural.

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Specific diagnosis.

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You see the vertebral segmentation

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abnormality here and here.

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So we know with that associated finding, high

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likelihood of being a neurenteric cyst.

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We have a component that is clearly intramedullary.

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Here's the spinal cord splaying out with the cyst

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in the spinal cord and you'll notice that there is

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narrowing of the cerebrospinal fluid when

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it comes to the lesion.

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However, we also will have a meniscus sign.

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So this portion of the cyst goes from being

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intradural intramedullary, to being intradural

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extramedullary

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behind the spinal cord with a meniscus,

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except that we also see this large cyst anteriorly.

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This is an extradural cyst.

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This is actually the enteric portion

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of the neurenteric cyst.

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So this has both intradural intramedullary,

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intradural extramedullary, as well as extradural

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components associated with vertebral segmentation

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anomaly and a fantastic case of neurenteric cyst.

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You'll notice that although I'm using the term cyst,

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it doesn't have CSF signal intensity.

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It actually has this intermediate signal intensity.

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It's filled with high protein secretions.

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Got to love it.