Presentation
Chronic headaches. Incidental finding on the MRI exam.
Patient Data
Age: 70 years
Gender: Female
From the case:
Epidermoid cyst - prepontine cistern
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Small extra-axial mass at the right aspect of the prepontine cistern, eliciting a low signal on T1, heterogeneous signal on FLAIR fat sat and high signal on T2 with restricted diffusion on DWI/ADC. no enhancement was seen on the postcontrast sequence.
Moderate cerebral volume loss with small vessel ischaemic change.
Case Discussion
MRI features most consistent with an epidermoid cyst of the prepontine cistern (incidental finding).
DWI is important to differentiate an epidermoid cyst from an arachnoid cyst (the arachnoid cyst follows the CSF signal on all sequences with no restricted diffusion).