Non-aggressive, sinus-type greater sphenoid wing dural arteriovenous fistula with shunt point in the laterocavernous sinus mimicking a cavernous sinus dural arteriovenous fistula converted to aggressive, non-sinus-type.

Sphenoid wing dural arteriovenous fistulae (DAVFs) are rare. Although the imaging findings of greater sphenoid wing DAVFs may resemble those of cavernous sinus DAVFs (CSDAVFs), their respective presentations differ. Benign CSDAVFs rarely convert to the aggressive type. Conversely, as greater sphenoid wing DAVFs are often of the aggressive type, with intracranial cortical venous reflux and varices, treatment is recommended. Sphenoid wing DAVFs tend to be of the non-sinus type, and transarterial embolisation is often an effective endovascular treatment. We present a case of an asymptomatic greater sphenoid wing DAVF mimicking a CSDAVF that converted from a non-aggressive sinus-type to an aggressive non-sinus-type due to compartmentalisation and thrombotic occlusion. Transarterial embolisation with Onyx and a transarterial venous coil resulted in complete disappearance of the DAVF. Greater sphenoid wing DAVFs can be misdiagnosed as CSDAVFs and require accurate imaging evaluation and careful follow-up, even in asymptomatic or non-aggressive cases.