Case of the Week

Axial T1 without contrast MR image (A) and axial T1 with contrast MR image (B) shows left sided proptosis due to a T1 hypointense, homogeneously enhancing, intraorbital mass (asterisk) with intracranial extension to the left cavernous sinus (blue arrow) where it encases the carotid artery without luminal reduction. There is also intracranial extension with dural thickening and enhancement (red arrow) in the left middle cranial fossa anterior to the temporal pole. There is also extension into the mid and posterior left ethmoid air cells and left sphenoid sinus (yellow arrows). 

Coronal T1 with contrast MR image (C) and coronal T2 with fat saturation MR image (D) shows the intraorbital mass (asterisk) is predominantly T2 hypointense with a small area of T2 hyperintensity. The mass engulfs the superior rectus and levator palpebrae muscles and is inseparable from the superior oblique muscle and lacrimal gland. The optic nerve sheath complex is displaced inferiorly (white arrow). There is intracranial extension with thin dural thickening and enhancement (red arrow) beneath the left frontal lobe in the anterior cranial fossa.