Idiopathic sclerotic inflammation of the orbit with left optic nerve compression in a patient with multifocal fibrosclerosis

Abstract

We present the MR imaging findings in a 43-year-old male patient with bilateral idiopathic sclerosing inflammation of the orbit. Bilateral enhancing retrobulbar masses, with concentric compression of the retrobulbar segment of the left optic nerve, were seen. MR imaging proved to be the only means to distinguish between the different intraorbital structures and to determine the exact site of optic nerve compression. To our knowledge, this is the first documented case of MR imaging findings of this entity.

fig 1.

Axial unenhanced T1-weighted scan (507/15/4) [TR/TE/excitations] of the anterior skull base. Extensive homogeneous, bilateral, intraconal masses with low signal intensity are visible. The conal muscles are displaced laterally (white open arrow). The ophthalmic artery is apparent at the apex of the orbit (small white arrow).fig 2. Axial enhanced T1-weighted scan (507/15/4) of the anterior skull base. Marked homogeneous enhancement of the intraconal masses (black arrow) is visible. The left optic nerve is encircled and compressed by the retrobulbar enhancing masses and appears thinned at its distal segment (curved black arrow). There is no pathologic enhancement of the intracranial structures.fig 3. Axial turbo spin-echo T2-weighted image (2000/120/6) of the anterior skull base. Bilateral, marked hypointense, intraconal, retrobulbar masses are visible. The laterally displaced conal muscles (white open arrows) and the posterior segment of the left optic nerve and its subarachnoid space (small white arrows) are clearly apparent. The more distal segment of the subarachnoid space of the left optic nerve is compressed (curved white arrow)

fig 4.

Coronal turbo spin-echo T2-weighted image (2027/120/6) of the anterior skull base. An expanding retrobulbar mass with low signal intensity is visible in the right orbit (white arrow). The conal muscles are displaced without signs of infiltration (small white arrows). In the medial and upper quadrant of this mass, the optic nerve and its subarachnoid space are clearly visible (open white arrow)