Middle cranial fossa arachnoid cyst

Case contributed by Dr Bruno Di Muzio


Presented with sudden onset headache.

Patient Data

Age: 42
Gender: Male

There is a fluid density collection in the left middle cranial fossa ( 3.5 x 4.7 cm ) with an imperceptible wall and thinning of the overlying bone in keeping with an arachnoid cyst. This could be confirmed on follow up MRI. It exerts mass effect on the left temporal lobe and left lateral ventricle.

No evidence of acute ischemia. No intra or extra-axial hemorrhage is seen. No hydrocephalus.

The fluid density collection in the left middle cranial fossa is again demonstrated and is in keeping with an arachnoid cyst. 

Case Discussion

Arachnoid cysts are relatively common benign lesions occurring in association with the central nervous system, both within the intracranial compartment (most common) as well as within the spinal canal. They are usually located within the subarachnoid space and contain CSF. 

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Case information

rID: 37762
Published: 23rd Jun 2015
Last edited: 10th Sep 2015
Tag: rmh
Inclusion in quiz mode: Included

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