Neonatal giant dural sinus ectasia: a multimodality imaging approach.

Dural venous sinus ectasia is a rare anomaly characterised by the formation of a large vascular lake within the leaves of the dural sinuses, usually associated with thrombosis. These lesions can cause brain compression, cardiac insufficiency and disseminated intravascular coagulation, which may lead to poor prognosis. We present the case of a neonate who presented with an intracranial mass on prenatal ultrasound. Postnatal transcranial ultrasonography, cranial CT and cranial MRI demonstrated a large lesion predominantly occupying the dural sinus confluence, extending into the sagittal sinus, straight sinus and right transverse sinus. The left marginal sinus remains unfused and patent. Concomitant arteriovenous malformations were evident in the median interhemispheric fissure and the left Sylvian fissure. There are several published case reports and case series describing malformations of the dural sinuses in perinatal and neonatal patients in recent years, but this case is unique in that: (1) there is the presence of a vascular malformation concomitant to the dural sinus ectasia and (2) it highlights the importance of imaging in clinching the diagnosis of giant dural venous sinus ectasia, as it is often misdiagnosed as more common conditions such as extra-axial intracranial haemorrhage.