Epidermoids can rutpure causing chemical meningitis.
This can lead to vasospasm which can lead to devastating infarcts
Case in Point
4.9.13 "White Epidermoid"
http://3s.acr.org/CIP/CaseView.aspx?CaseId=yAIg7PFcQTQ=
Reference:
http://thejns.org/doi/pdf/10.3171/JNS-07/08/0426