Dural Arteriovenous Fistula Mimicking a Supratentorial Tumor

Dural arteriovenous fistulas misdiagnosed as intracranial neoplasms: illustrative case

BACKGROUND

Dural arteriovenous fistulas (dAVF) may induce imaging findings attributable to various disease entities including malignant neoplasms. In these cases, diagnosis and adequate treatment are often delayed and patients may be exposed to spurious treatments in addition to the risks inherent to an untreated dAVF with cortical venous drainage.

OBSERVATIONS

The authors report a case of a patient referred for surgical treatment of a supratentorial high-grade glioma. Thorough review of imaging data challenged the initial radiological diagnosis and led to proper angiographic workup. As a result, a high-grade dAVF was confirmed and successfully embolized. In addition to this case, we provide an extensive literature review on dAVF initially diagnosed as cerebral neoplasms, including clinical, imaging and follow-up data.

LESSONS

The literature provides diagnostic criteria for dAVF on magnetic resonance imaging; however, those criteria may be only partly applicable in many cases. Misdiagnosis of a neoplasm due to dAVF has been reported but remains rare, especially in supratentorial lesions. Digital subtraction angiography should be pursued to rule out an underlying vascular pathology if any doubt. This may prevent unnecessary interventions such as biopsies, pharmacological treatment and a delay in dAVF treatment, given its associated risk of hemorrhage and nonhemorrhagic neurological deficits.

Brain arteriovenous malformations and dural arteriovenous fistulas with extensive venous congestive encephalopathy

In brain arteriovenous malformations (BAVMs) and dural arteriovenous fistulas (DAVFs), when too much blood is drained into the venous system, extensive venous congestive encephalopathy (EVCE) can appear. EVCE in BAVMs and DAVFs can be divided into acute and chronic stages. BAVMs and DAVFs have their own classification systems, but EVCE is not considered in these classification systems and needs to be emphasized. EVCE in BAVMs and DAVFs has unique clinical and imaging features. The clinical presentations usually consist of headache, cognitive impairment, and focal deficits. EVCE in BAVMs and DAVFs has several imaging features, and the venous congestion seen on computed tomography angiography and magnetic resonance angiography can present with the angiographic features of venous reflux and pseudophlebitic pattern. Digital subtraction angiography is the gold standard for the diagnosis. Delayed circulation time is observed. Tortuous, dilated, and engorged veins can be seen. For EVCE from BAVMs and DAVFs, prompt treatment is warranted due to the impairment of extensive brain tissue. Treatments include endovascular treatment (EVT), open surgery, and radiosurgery. EVT is often the primary treatment. Complete elimination in one stage is often difficult. Most of the time, staged treatment has to be chosen. No matter at the acute or chronic stage, aggressive treatment is recommended.