Teaching Case

A 59-year-old woman consulted for a 3-month difficulty closing the right eye not associated with ptosis nor diplopia.
On neurological examination the patient had right upper facial weakness, hypoesthesia in the distribution of V3 of the right trigeminal nerve and mild right hearing loss.

An initial brain CT without contrast enhancement was performed with no significant findings.
Cerebral Magnetic Resonance Imaging (MRI) showed a nodule of 6 mm of diameter in the right cerebellar hemisphere having popcorn appearance with hypointense halo in T2-weighted imaging (haemosiderin rim) and no enhancement with gadolinium, suggestive of cavernoma.
Brain contrast enhanced MRI revealed prominent veins in the right cerebellar hemisphere with multiples small ramifications showing caput medusae appearance draining into the right petrosal vein and partially occupying the right cerebellopontine angle (prominent right petrosal vein), suggestive of developmental venous anomaly.
Seventh and eighth cranial nerves showed no intrinsic pathology.

Developmental venous anomaly (DVA), called venous angioma in the past, is a congenital cerebral vascular malformation with mature venous elements. DVA is a benign anatomic variation of normal venous drainage and is usually discovered incidentally [1].
DVA is the most frequently encountered cerebral vascular malformation [2].
Cavernous malformation (CM) or cavernoma is a benign vascular hamartoma with intralesional haemorrhages, no neural tissue [3].
Patients with DVA are usually asymptomatic and patients with CM present seizures or neurologic deficits. In 20% of cases patients with cavernous malformation are asymptomatic.
DVA is associated with CM in 13%-40% of cases [4, 5, 6].
DVA is present at all ages and CM has a peak presentation at 40-60 years.

Imaging findings:
- DVA:
On non-contrast CT: normal or the collecting vein of the DVA may appear to be isodense or slightly hyperdense. In some cases it is possible to see parenchymal calcification if mixed cavernous malformation is present.
Non contrast CT may disclose an associated haemorrhage.
On contrast-enhanced MRI: Collection of enlarged medullary veins ("caput medusae") that converge on enlarged collector vein.

- CM:
On non-contrast CT: normal in 30-50%, hyperdense ovoid lesion.
Contrast enhanced CT: little or no enhancement.
MRI: T1-weighted image, variable with mixed hyperintensity and hypointensity areas.
T2-weighted image: popcorn-like lesion with complete hypointense haemosiderin rim [3]
T2*GRE: hypointense blooming.
Contrast enhanced MRI: minimal or no enhancement.

The haemorrhagic risk of CM associated with DVA may be higher than the 2.6% and 3.1% per patient-year reported for isolated CM [2, 7]

In our case the patient’s symptomatology led the physician to request an imaging test.

In a second control three months after the brain MRI the patient shows no clinically relevant changes. Conservative treatment and clinical - neuroradiological follow-up was recommended.

It is recommended to search for associated vascular malformations when a developmental venous anomaly is discovered.