A markedly T2 hyperintense lobulated mass arising from the right aspect of the clivus corresponding to a relatively homogeneous T1 iso/ hypointensity with heterogeneous enhancement post contrast is noted. No associated diffusion restriction.
The mass exerts mass effect on the right side of the pons, however the 4th ventricle and cerebral aqueduct remain capacious and there is no hydrocephalus. Adjacent flow void within the right petrous/cavernous ICA is preserved. No other intracranial or skull base lesion seen.
Marked T2 hyperintensity can be seen with either chondroid lesions or chordoma. Less likely differentials include an ecchordosis physaliphora, cavernous sinus haemangioma and least likely (given morphology) a schwannoma.
Overall features favour a chondroid series tumour (including chondrosarcoma), although chordoma can occur off midline and evoke bony erosion/sequestration which can mimic a similar pattern of bony change.
Further assessment with CT to evaluate matrix calcification/ossification and bony margins is recommended.