Cavernous Angioma

This 64 year old lady had a known history of a pontine cavernous malformation which was being followed up by MRI following stereotactic radiosurgery. This T2 weighted axial MRI image shows a typical reticulated “popcorn-like” lesion in the left dorsal pons adjacent to the floor of the fourth ventricle. It has a peripheral low signal rim of haemosiderin.
Cavernous malformations are vascular malformations with endothelial proliferation and increased neoangiogenesis. The prevalence is approximately 0.5%. 75% occur as solitary sporadic lesions, whilst 10-30% of cases have multiple lesions and a familial inheritance. Males and females are equally affected. Peak presentation is between 40 and 60 years but they may present in childhood. They may be asymptomatic or manifest with seizures or neurologic deficits. The natural history is variable with enlargement or regression, and new lesions can develop. The risk of intralesional haemorrhage is about 0.25-0.70% per year for sporadic lesions, and approximately 1% per lesion per year for familial cases.
Reference: Osborn et al. Pocket Radiologist: Brain Top 100 Diagnoses. Amirsys 2002.
Credit: Dr Bernard Ng
http://www.radpod.org