|Print Date:||May 21, 2013, 8:31 pm|
|Title||Colloid cyst, neuroepithelial cyst|
|Text||Colloid cysts are uncommon benign cysts of the anterior superior third ventricle, which are thought to arise from embryologic tissues of the paraphysis, ependyma, or choroid plexus. These lesions typically present in young adults in the 2nd to 5th decade with complaints referable to acute or chronic hydrocephalus. Other symptoms include ataxia, memory disturbances, and gait disorders. The cyst contents include secretory and breakdown products of the epithelial lining tissue, including hemorrhage, lipid (cholesterol), hemosiderin, and CSF.
On T1-weighted MR images, these cysts vary widely from hypo- to hyperintense in comparison to normal brain. Although they may be bright on T2-weighted images, moderate to marked hypointensity is common and has been attributed to a very short T1 relaxation time or to magnetic susceptibility effect from paramagnetic substances in the cyst. On noncontrast MR, these lesions occasionally are indistinguishable by intensity from neoplasia; however, the absence of enhancement, classic location, and relative hypointensity on T2-weighted studies should suggest this diagnosis. Treatment is variable, including ventricular shunting alone, stereotactic cyst drainage, or surgical resection.
On noncontrast CT, colloid cysts are solitary, round to oval, usually hyperdense masses at the foramen of Monro with associated enlargement of one or both lateral ventricles (Film .3). Minimal or absent contrast enhancement is typical. Moderate enhancement with contrast suggests a different etiology, such as glioma, craniopharyngioma, choroid plexus papilloma, or remotely meningioma. Other cystic masses such as arachnoid or ependymal cysts will mimic CSF in density and intensity.
Video - http://www.youtube.com/watch?v=9NbKjXChneo&
|Contributor||Russell A. Patterson (Uniformed Services University)|
|Peer Reviewer||James G. Smirniotopoulos, M.D. (Uniformed Services University)|
|Record Number||: 7652|
|Location:||Brain and Neuro|
|MedPix® Medical Image Database |
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