Cavernous Sinus Dermoid Cyst

Clinical History : 60yr old female patient with right 3rd nerve palsy. Suspecting a PCom aneurysm, CT angiogram was performed which showed no intracranial aneurysms.

However a heterogenously hypodense non-enhancing lesion was seen in the right cavernous sinus, with cavernous ICA seen medially displaced. Lesion anteriorly showed markedly hypodense area of negative attenuation varying from -100 to -150HU, suggesting intralesional fat. Posterior rim of the lesion showed small calcfications. Lateral hyperdense rim was thought to represent the thickened dural layer of cavernous sinus.