Presentation
Deterioration in mental function with possible stroke, ? vascular lesion
Patient Data
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Mass lesion arising in the pituitary fossa extending on the left side into and expanding the cavernous sinus, encasing the distal left internal carotid artery (arrow). Note the cavernous sinus has a convex outer border on the left as compared to concave on the right.
Case Discussion
Extension of a pituitary tumor into the cavernous sinus is often difficult to be certain on CT (or MRI for that matter). The ICA is critical. If tumor encases or at least 75% surrounds the distal ICA then cavernous sinus infiltration is likely as the vessel traverses the cavenous sinus.