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Hello, welcome back to Pro Scan MRI Online.

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My name is Dr. Benjamin Laser,

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neuroradiologist,

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and we are going to continue our case discussion

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on non-glial CNS brain tumors.

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This patient is a 43-year- old woman who presents

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with headache, and as you can see,

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there is a well-defined smooth lobulated mass within

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the right lateral ventricle.

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On T2-weighted imaging,

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the mass is usually heterogeneous with the soft tissue

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solid components being isointense

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to adjacent brain parenchyma.

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The cysts are hypointense on the T2-weighted sequence.

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In the center panel,

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the cysts are hyperintense and the mass soft tissue

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is isointense to adjacent brain parenchyma.

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And on the far right panel, our FLAIR sequence,

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the mass typically has heterogeneous appearance

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and hyperintense to adjacent brain parenchyma.

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These findings are most consistent with the central

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neurocytoma. After contrast is administered,

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these lesions have moderate to strong

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heterogeneous enhancement.

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Calcification is a common finding in these lesions and the

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calcification would be hyperintense on T2 weighted

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sequence or have blooming artifacts on T2* sequence.

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If spectroscopy was performed,

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these lesions have elevated choline

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peak and decreased NAA peaks.

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The glycine peak can be seen at 3.5 parts per million

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and the alanine peak is variable FDG PET imaging.

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These lesions have hypometabolism and MRI is the most

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sensitive examination to evaluate these lesions.

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Central neurocytoma are usually located

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within the lateral ventricles.

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About 50% of the time in the frontal horn or body of

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the lateral ventricle near the foramen of Monro.

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15% of the time these lesions extend to the third

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ventricle and they can be seen in both outer ventricles,

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about 13% of the time and only about 5% of the time.

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They can be seen isolated to the third ventricle.

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They have rare extraventricular extension and

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the size can be variable as described.

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The morphology is typical for a circumscribed

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mass with lobulated margins,

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intraoral cysts and a bubbly appearance

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on imaging studies.

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These tumors likely arise from neuroglial or bipotential

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progenitor cells. Perronova is extremely rare,

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and they are considered a WHO grade two

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lesion.

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The most common signs and symptoms for these tumors

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include headache, increased intracranial pressure,

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mental status changes and even seizure.

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Other signs and symptoms include hydrocephalus,

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secondary to obstruction as these masses can typically

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be seen at the foramen of Monro causing

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obstructive hydrocephalus.

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If the tumor is isolated to the third

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ventricle or near the hypothalamus,

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these patients can present with visual disturbances

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or even hormonal dysfunction.

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Central neurocytoma are rarely asymptomatic.

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They occur in young adults ages 20 to 40 years,

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approximately 70% of the time, the mean age is 29 years.

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There is no gender predilection.

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These account for less than 1% of all

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primary intracranial neoplasms.

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These tumors represent 50% of intraventricular

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tumors in patients 20 to 40 years of age.

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Central neurocytoma are benign tumors

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and local recurrence is uncommon.

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They are rarely complicated by hemorrhage

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and CSF dissemination is extremely rare.

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Complete surgical resection is the treatment of choice.

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And if the surgical resection is incomplete,

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additional treatment would include radiation therapy,

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chemotherapy, and or radiosurgery.

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Differential diagnosis for these tumors would include

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subependymoma which could be indistinguishable

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from a central neurocytoma.

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If the central neurocytoma is small

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and more solid appearing, however,

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subependymomas usually occur in older patients

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and have very faint to no enhancement,

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and the location helps differentiate the diagnosis.

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Subependymomas usually happen in the fourth ventricle

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much greater than the lateral ventricle.

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Another differential diagnosis would include

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suboptimal giant cell astrocytoma.

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These tumors usually arise near the foramen of Monroe;

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calcification is extremely common. However,

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there would be many additional findings for the stigmata

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of tuberous sclerosis, such as subependymal nodules,

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cortical tumors, or white matter lesions.

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Another differential could be an intraventricular

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metastasis. However, those are extremely uncommon,

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and those would be in an older population.

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The primary tumor is usually known

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for intraventricular metastasis.

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Another differential consideration would

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include choroid plexus papilloma.

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These lesions are usually in younger patients within the

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lateral ventricle but predominantly

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within the fourth ventricle.

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They are intensely enhancing with papillary

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or frothy-like projections,

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and hydrocephalus is extremely common

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with a choroid plexus papilloma.

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Meningioma is also another differential consideration.

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These tumors are circumscribed, intensely enhancing,

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and usually at the trigone of the lateral ventricle.

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Again,

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age is a very important discriminator

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when describing these lesions,

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and intraventricular meningiomas usually happen in the

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older population. So take-home points for this lesion:

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when you see a lesion within the ventricle,

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that is well-defined intraventricular cysts, bubbly,

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feathery near the septum pellucidum or attached to

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the septum pellucidum, think central neurocytoma.