Aberrant arachnoid granulation

Case contributed by Dr Mostafa El-Feky



Patient Data

Age: 15 years
Gender: Male



Normal brain study.

A well-defined CSF-containing sac like structure is seen protruding into left occipital dura with related scalloping of occipital bone with no diffusion restriction, suggestive of an aberrant arachnoid granulation.

Annotated images


Arrows point to the arachnoid granulation.

Case Discussion

MRI features are suggestive of left sided occipital aberrant arachnoid granulation, that penetrated the dura. It is an incidental finding and not related to patient's complain. 

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