A huge mass arising within the scalp slightly to the right of midline at the vertex measures up to 7cm in width. It erodes through the underlying skull vault slightly to the right of midline in the parietal region entering the cranial cavity and invading the dura including the superior sagittal sinus with extrinsic compression of this structure but no definite thrombosis at this time. Multiple surrounding venous collaterals on the venogram.
Further infiltration into the brain parenchyma on the right with vasogenic-type oedema involving the right parietal lobe at the vertex. This would explain the patient's left arm weakness. No associated haemorrhage. No other specific intra-cranial abnormality is detected.
Appearances are indicative of a very aggressive SCC of the scalp that has extended through the skull vault into the cranial cavity in the region of the superior sagittal sinus and to the right encasing the sinus and causing extrinsic compression but no thrombosis at this time.
Further pial invasion to the right of midline into the parietal lobe with resultant vasogenic-type oedema and mass effect. This is no doubt responsible for the patient's left-sided neurological deficit.