Extra-axial intermediate T2 signal avidly enhancing lobulated lesion is noted centred on the right greater wing of the sphenoid / squamous temporal bone. There is destruction of the calvarium with extension into the overlying temporalis muscle. On CT scan, the bony margins are quite destructive. Slight reduction in diffusion is noted in the lesion suggestive of a cellular lesion. The lesion measures 2.9 x 5.5 x 4.6 cm (trans x ap x cc). Small amount of associated dural thickening is noted. The lesion appears to be solitary. Underlying vasogenic oedema is noted in the temporal and frontal lobe with slight mass effect. Given the degree of osseous destruction the possibility of a more aggressive lesion such as a haemangiopericytoma or a metastases (if the patient is known to have a malignancy) should also be considered.