Giant cell tumor of bone
Giant cell tumor of bone is a locally aggressive but histologically benign neoplasm of RANKL-expressing mononuclear cells and reactive osteoclast-like giant cells that classically produces an eccentric, expansile, lytic ('soap bubble') lesion at the epiphysis of a long bone in a skeletally mature young adult, confirmed by biopsy and treated with complete surgical resection or, when unresectable, denosumab.
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What this article covers
- Overview
A benign but locally aggressive bone tumor: giant cell tumor of bone is composed of neoplastic mononuclear cells that express receptor activator of nuclear factor kappa-B ligand (RANKL) admixed with…
- Epidemiology
Peak age 20-40 years: the tumor characteristically occurs after the growth plate has fused, distinguishing it from most other benign bone tumors, which cluster in younger patients.
- Risk factors
Age 20-40 years (post-skeletal-maturity), the dominant risk marker, since the tumor essentially does not occur before growth plate closure.
- Pathophysiology
Neoplastic mononuclear stromal cells drive the tumor: the mononuclear cell population is the true neoplastic component and expresses high levels of RANKL.
- Clinical features
Pain and swelling near a joint, without a history of trauma: the earliest and most consistent presenting complaint, typically insidious in onset.
- Differential diagnosis
Osteosarcoma: malignant, classically metaphyseal (not epiphyseal) in the young, shows Codman triangle or sunburst periosteal reaction rather than a soap-bubble lytic pattern, and biopsy shows…
- Diagnosis
Biopsy is the confirmatory test and establishes the diagnosis: tissue demonstrates neoplastic mononuclear cells with high RANKL expression admixed with reactive multinucleated osteoclast-like giant…
- Management
First, establish surgical candidacy and resectability based on tumor size, location, and relationship to the adjacent joint and neurovascular structures, which determines the branch point below.
- Complications
Pathologic fracture: cortical thinning from the expanding lytic lesion predisposes to fracture with minimal trauma, sometimes the presenting event.
- Prognosis
Generally favorable given the tumor's benign histology, but local behavior determines long-term outcome more than the risk of distant spread.
- Prevention
No primary prevention exists because there is no identified modifiable risk factor or screening test for sporadic giant cell tumor of bone.
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