Carotid cavernous fistula masquerading as orbital inflammation on noninvasive imaging in a peripartum patient.

A carotid cavernous fistula (CCF) is a pathological connection between the internal or external carotid artery and the cavernous sinus venous system. Pregnancy has been proposed as a risk factor for spontaneous CCF, but the exact mechanism of risk is unknown. Overall, there are few published reports describing CCF in pregnancy. Study of this risk factor relationship is further complicated by potential ambiguity in diagnosing CCF, which may present as subtle, nonspecific findings on initial workup. We report a case of CCF during pregnancy in which the diagnostic process was notable for misleading, noninvasive, imaging studies.