Centred on the left tectal plate is a 8 x 12 x 20mm hyperdensity with foci of calcification. It appears separate from the pineal gland. Third and lateral ventricles are prominent for sulcal pattern although the temporal horns are not dilated. No intra- or extra-axial collection or haemorrhage demonstrated. No bony abnormality demonstrated.
Conclusion: Tectal hyperdense calcified mass lesion with mild hydrocephalus is most likely a tumour (such as tectal glioma or gangliolioma) with non-neoplastic mass (such as cavernoma) a differential. MRI would be helpful for further evaluation.