This brain has been sliced in the mid-sagittal plane. It comprises a whole hemi-section of the brain about 1cm thick. On the medial surface a large darkly-coloured ovoid berry aneurysm measuring 5 x 2 cm in diameter, arising from the basilar artery is clearly visible. It has eroded up into the midbrain, compressing the third ventricle from below, and inferiorly into the substance of the pons. The wall of the aneurysm appears intact although blood clot is seen in the third ventricle and appears to be leaking through the lateral wall of that ventricle. The aneurysm is filled with a laminated thrombus. A small area of mucoid degeneration measuring 0.4 cm in diameter is seen posterior to the aneurysm within the pons.

Examination of the lateral aspect of the sagittal section shows dilatation of the lateral ventricle, blood staining of the ventricular wall and patchy haemorrhagic infarction of the caudate nucleus. There was some discolouration of the meninges overlying the tip of the left temporal lobe and the cerebellum (not included in 3D print), consistent with sub-arachnoid haemorrhage.