Nurhayati Abdul Kadir¹, Syed Shoeb Ahmad^1,, Shuaibah Abdul Ghani¹

Idiopathic orbital inflammatory disease (IOID) is a common orbital disorder. However, it has a highly variable clinical presentation depending on the site, degree of inflammation and size of the lesion, which produces a mass effect in the orbital cavity. IOID has no pathognomonic clinical features, thus radiologic and occasionally histopathologic studies are required to confirm the diagnosis of IOID. Here we report a case of a healthy elderly gentleman who presented to us with proptosis, dilated and tortuous conjunctival and retinal vessels and a positive response to Valsalva maneuver. These clinical features were suggestive of a carotid cavernous fistula (CCF). An initial CT scan showed an intraconal orbital mass. Hence, an MRI was subsequently performed which did not show features of CCF, however, there was again a large intraorbital mass noted. The radiologic differential diagnosis suggested was IOID, lymphoma and metastasis. Hence, a biopsy of the intraorbital mass through the transnasal approach was performed. That confirmed the lesion to be IOID and not CCF. Hence, although proptosis with conjunctival congestion, dilated tortuous conjunctival and retinal vessels with positive Valsalva maneuver are the usual clinical features of CCF, this case illustrates these features may also occur in patients with IOID.

orbital inflammatory pseudotumor, carotid cavernous sinus fistula, Valsalva maneuver, inflammation, proptosis