Fact-sheet: Giant cell tumor - Tumor of myeloplexus
Updated on 09/28/2019 at 10:39 AM
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Definition
Locally aggressive benign primary bone tumor, with a tendency for local recurrence, most often epiphyseal in location, highly vascularized, composed of a dual cellular population: giant cells and mononuclear elements.
Clinical features
80% of cases occur between 20 and 50 years of age, with a predominance between 20 and 30 years, 99% after growth plate closure.
Nonspecific clinical presentation.
Pain, swelling, limitation of joint range of motion.
Occasionally, joint effusion or pathologic fracture.
Possible nerve compression in cases of spinal involvement.
Possible incidental discovery.
Pulmonary metastases are rare (1-2% of cases).
Radiography
Typically: a monostotic, purely lytic lesion, eccentric, well-defined, without intralesional matrix or peripheral sclerosis, extending to the subchondral bone. Sometimes: - Peripheral sclerosis (1-2% on radiographs, up to 20% on CT) - Geographic lysis with a wide zone of transition (10-20%) - Expansile remodeling of adjacent healthy bone (47-60%) - Cortical involvement (33-50%) - Soft tissue mass (33-44%) - Periosteal reaction (10-30%), occasionally due to a pathologic fracture. - In small bones: a more central than eccentric location.
CT
Without contrast injection. Not useful in typical forms. Osteolysis with tissue content (isodense to muscle), with internal septa. Look for: - absence of intratumoral bone matrix, - cortex (thinning, expansion, cortical breach), - +/- periosteal reaction or expansile bone remodeling, - +/- areas of tissue necrosis, - extraosseous extension (33-44%), - +/- fluid-fluid levels.
MRI
Indications: Suspicion of malignancy, locoregional staging, prior to biopsy.
Intermediate signal on T1, often heterogeneous on T2.
T2 hyposignal, inconstant, is highly suggestive of the diagnosis.
Often hyperintense on T2 FatSat or STIR.
Perilesional sclerosis or capsule --> Peripheral rim of low T1 and T2 signal.
After injection: enhancement of tissue components.
Assessment of extension into adjacent soft tissues (
most often at the metaphyseal portion).
Evaluation of the tumor's relationship with adjacent vessels.
Strong propensity to cross joint spaces (sacroiliac joints, intervertebral disc spaces).
Nuclear medicine
More marked uptake at the center of the lesion.
Hyperemia on the opposite side of the joint space (62%).
Management
Surgical treatment. - Curettage and filling: minimally progressive lesions, without articular extension, not previously operated on. Filling with autograft, bone allograft, or cement. or - Surgical resection: aggressive lesion, with soft tissue extension or in cases of recurrence. Inoperable forms: Radiotherapy (may induce malignant transformation). Sacral form: Arterial embolization sometimes indicated.
Classification
Multiple forms (0.5-5%):
- rarely associated with Paget disease,
- rule out brown tumors in the setting of hyperparathyroidism,
- may be synchronous or metachronous.
Malignant forms:
- sarcomatous transformation < 5% during the first five years,
- cortical breach,
- soft tissue mass.
Pulmonary metastases from benign giant cell tumors are possible.
Differential diagnosis
Brown tumor
Chondroblastoma
Clear cell chondrosarcoma
Aneurysmal bone cyst
Telangiectatic osteosarcoma
Plasmacytoma
Aggressive hemangioma
Sacral chordoma