Haemosiderin cap sign – a spinal tumour appearance where a cap of hypointense haemosiderin is seen on T2 weighed imaging above and / or below the tumour due to previous haemorrhage. It is most often associated with spinal ependymomas, being seen in 20-33% of these cases. The sign however may also be seen in hemangioblastomas and paragangliomas and therefore while it is highly suggestive of ependymoma it is not pathognomonic.
See our YouTube video tutorial on ‘Spinal Ependymoma’ here.
from our tumblr blog