Femoral Neck-Aneurysmal Bone Cyst
22 year old male with history of fall and pain right hip. X-ray shows expansile lucent predominantly intramedullary, femoral neck lesion with normal hip joint. MR shows grossly expansile septated, predominantly fluid signal intensity space occupying lesion with cortical breaches, bleed, soft tissue edema in the vicinity – Features are suggestive of aneurysmal bone cyst.
Teaching Points by Dr MGK Murthy, contributors-Mr Hariom Sharma
ABC is non-neoplastic expansile lesion consisting of blood filled spaces separated by connective tissue septa containing bone or osteoid and osteoclast giant cells
Etiology unknown
May be primary or secondary ( in about 30 % of associated bone tumors).
CT suggests 20 HU as approximate density with presence of blood and fluid levels.
Double density fluid levels on MR are suggested as quite specific to ABC.
Differential diagnosis includes Simple Bone cyst (Centrally located with no expansion / cortical breach), GCT (more than 20 years of age, no significant expansion and predominantly epiphyseal lesion), Osteoblastoma (usually diaphyseal, no fluid / fluid levels or cortical breach), Telengiectatic osteosarcoma / Angiosarcoma (difficult to differentiate from agressive ABC).
Femoral Neck-Aneurysmal Bone Cyst
Reviewed by Sumer Sethi
on
Monday, October 03, 2011
Rating:
4 comments:
Hi,
Another great case, thanks for sharing.
Were there any fluid fluid levels? You did not show any.
Given the location and femoral deformity, I would also consider fibrous dysplasia.
Keep these great cases and discussions coming!
Best regards,
Brian Sabb
www.linkedin.com/in/briansabb
Thx for your encouragement
there were no fluid fluid levels
my idea is to bring the clinical queries as they come to our table every day so that teaching is dynamic
Yes but why not fibrous dysplasia?
classically fibrous dysplasia should produce all the three regions as seen on Xray and extrapolatable on other imaging - areas of lucency, sclerosis and ground glass opacities
secondly it should also produce typical deformity tending towards shepherds Crook as we know it
Thirdly Soft tisseus should be as normal as possible
Having said that, we should consider it in the D/D and Fibrosarcoma arising as complication of FD needs mention here
thx for sharing, would have app if you were not anonymous
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