Kevin Hoover, Bruno Vandeberg and Jenny Bencardino all suggested that this might be Hydroxyapatite Deposition Disease.It makes perfect sense given the mismatch T1 / PDFS appearance in bone and the exaggerated reactive soft tissue edema!
I had recommended CT (don’t have f/u imaging as yet), but now it seems XRs might suffice.
It’s great to get a little help from your friends!
Hilary
On Wed, May 21, 2025 at 8:00 AM hilary wrote:
The only history I have is knee pain, no trauma. The subcortical lesion of the medial supracondylar femur was not present in an MRI from 2016.
Currently there is synovial thickening, periosteal edema and posteromedial intermuscular edema in addition to the bone lesion.
On the only T1 weighted (axial) series, there is a cluster of dark signal foci with preservation of bright T1 signal between the dark foci
There is overlying cortical thickening and subtle spiculation
The mismatch in the appearance of the bone lesion on PDFS is confusing
It seems to me that the extensive synovial thickening (without cartilage thinning) might be related.
I have recommended CT to better characterize the medullary lesion.
I’m not convinced this is neoplastic….
Any ideas?
