Dural sinus thrombosis presenting as unilateral lobar haematomas with mass effect: an easily misdiagnosed cause of cerebral haemorrhage.

Dural sinus thrombosis has protean clinical and radiological manifestations ranging from minimal effacement of sulci with no symptoms to severe haemorrhagic infarcts associated with focal deficits, coma and even death. An uncommon form of presentation is characterized by unilateral lobar haemorrhage associated with extensive oedema and parenchymal distortion. In an acute presentation, this might resemble haemorrhage into a tumour. In delayed presentations, the haematoma, being iso- or hypodense and showing peripheral ring-like enhancement, can mimic aggressive tumours or infective processes. As this is an uncommon condition, misdiagnosis is common with the potential for mismanagement and adverse outcomes. We present five such consecutive cases that were initially misdiagnosed as other entities. Each of these cases on closer inspection show features observed on CT and MRI that should have suggested a diagnosis of dural venous sinus thrombosis. One of these cases progressed to not only extensively involve the superficial sinuses but also the deep veins, with a significant adverse outcome. The imaging features of this interesting variant of dural sinus thrombosis are reviewed. The haemodynamic basis for haemorrhage and anatomical basis for the lateralization of the lesions are discussed.