Giant cell tumor of bone and tenosynovial tissue : surgical outcome

Abstract

Giant cell tumor of bone (GCTB) is an intermediate, locally aggressive but rarely metastasizing tumor. Radiologically, GCTB shows typical lytic lesions. MR imaging is required to evaluate extent of GCTB for surgical planning. Preferred treatment for GCTB is extended curettage with local adjuvants, with comparable recurrence rates for different local adjuvants (27-31%). Resection can be performed when joint salvage is not feasible. Denosumab (RANKL-inhibitor) blocks and zoledronic acid (bisphosphonate) inhibits GCTB-derived osteoclast resorption. With zoledronic acid, stabilization of local and metastatic disease has been reported. Denosumab has been studied to a larger extent and seems to be effective in enabling less invasive forms of surgery. Moderate dose radiotherapy should be restricted to rare cases of unresectable or recurrent GCTB when surgery would lead to unacceptable morbidity. Tenosynovial GCT are classified into localized GCT of tendon sheath (GCTTS; nodular tenosynovitis) and diffuse-type GCT (Dt-GCT; pigmented villonodular synovitis, PVNS). Although arthroscopic synovectomy has been advocated as alternative to open synovectomy, there is a significant risk of inadequate excision. For GCT-TS, arthroscopic synovectomy may be sufficient. For Dt-GCT, open synovectomy is advised. For recurrent and extra-articular disease, moderate dose radiotherapy or systemic targeted therapy (M-CSFR-targeted tyrosine kinase inhibitors, e.g. imatinib) can be considered.