Case Number : Case 1722 - 3 January - Dr Uma Sundram Posted By: Guest

I am away on holiday in lovely Italy so am posting all this week's Spot Diagnosis Cases in one go. Here is Dr Uma Sundram's excellent case for you to work on.

Ciao, Geoff Cross - DermpathPRO Projects

Giant cell tumor of soft tissue

Yes, I also thought of giant cell tumor of soft tissue

Yes giant cell tumor of soft tissue. Important to indicate a clinicopathological correlation in the diagnosis as a recidive of giant cell tumor from bone infiltrating soft tissues is not possible to perform accurately based on histology alone

Giant cell tumor of soft tissue, but metastasis or extension from its aggressive osseous counterpart must be rule out.

Great osteoclast-like giant cells, presumable osseous metaplasia (of course rule out bone erosion, but less likely); no perceivable cellular atypia in the mononuclear population, no mitoses, no necroses and a hint of circumscription (Image 1; top right). 
I also go for Giant cell tumour of soft tissue.
Very nice case :)

Agree, giant cell tumour of soft tissue.

Agree with GCT of soft tissue.

Giant cell tumor. Excellent point by Raul. It turns out the patient had a bony giant cell tumor and this was a direct soft tissue extension. A very unusual case and i was glad to be able to see it. I think the 'hint' of circumscription is very unusual and somewhat misleading. Great point to do (always) clinicopathologic correlation.