Pathological characteristics of giant cell tumor of bone treated with denosumab

الملخص EN

We present a Giant Cell Tumor of Bone (GCTB) in a patient who presented with pathological fracture of the lower end of the femur.

The patient was treated with Denosumab, an anti-RANKL inhibitor for four weeks followed by intralesional excision, screw reinforcement and bone cementation.

Denosumab prevented the proliferation of stromal cells and osteoclastogenesis of the GCTB leading to its replacement by a fibrohistiocytic lesion (FHL) which has similar microscopic and immunohistochemical reactivity as that of fibrous histiocytoma.

It increased the formation of reactive bone.

The patient was followed up for six months with no recurrence or activity.

We describe and interpret the microscopic and immunohistochemical (IHC) post-Denosumab bone changes and the role of fracture repair and bone cementation in the organization of the FHL.