Arachnoid cyst

Case contributed by Dr Jeremy Jones


Acute confusion following a fall.

Patient Data

Age: 85
Gender: Male

There is a 5x3cm low attenuation lesion in the left frontotemoral region. It is located within the CSF space, and has mass effect, including displacement of the cortex, effacement of the left lateral ventricle and midline shift.  Thinning and remodelling of the adjacent bone is also noted. 

Annotated image

CSF density arachnoid cyst ( * ) displacing the adjacent cortex is associated with bony thinning / remodelling (blue arrow). 

Case Discussion

This case demonstrates characteristic appearances of an arachnoid cyst. These are relatively common lesions and in most cases are asymptomatic and found incidentally. 

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Case information

rID: 13215
Published: 15th Mar 2011
Last edited: 16th Oct 2015
Inclusion in quiz mode: Included

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