This is an entity that may not recognized by some radiologists. Proper diagnosis will direct surgical treatment, which can halt progression of/reverse symptoms.
HSS 2710816
thanks to Vikash Singh '15
References:
ACR Case in Point (11/12/10)
http://3s.acr.org/cip/ArchiveCaseView.aspx?CaseId=S7IeJhe6gyw%3d
Radiographics