Arachnoid cyst - lateral cerebellomedullary cistern

Case contributed by Dr Bruno Di Muzio


Incidental finding in the posterior fossa.

Patient Data

Age: 43-year-old
Gender: Female

MRI Brain (selected images)

There is a well-defined cyst lesion in the left lateral cerebellomedullary cistern, following the CSF signal in all the sequences, and not showing diffusion restriction. There is mild chronic impression over the adjacent temporal bone.

Case Discussion

The arachnoid cyst represents a benign condition, and the primary differential is made with an epidermoid cyst. However, this was easily ruled out using the DWI/ADC sequences, which did no demonstrate diffusion restriction. 

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Case information

rID: 43347
Published: 7th Mar 2016
Last edited: 7th Mar 2016
Inclusion in quiz mode: Excluded

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