Giant Cell Tumour

Giant Cell Tumour

By Dr. KM Liau

Giant cell tumour is a benign but locally aggressive tumour with a potential to metastasize.

Incidence

This lesion almost always affects mature skeleton with closed epiphyseal plates.

Approximately 70% of patients are between 20 and 40 years old.

The peak incidence is in the 3rd decade of life.

Approximately 60% of giant cell tumours occur adjacent to the knee joint.

Distal radius is the 2nd most common location.

Multicentric giant cell tumours are rare; accounting for less than 1% of all giant cell tumours.

Imaging

Plain X-ray findings often are diagnostic.

The lesions are :

1. Eccentrically located in the epiphyses of long bones.

2. Juxtarticular (abuts the subchondral bone).

3. Purely lytic. Do not have a rim of sclerotic bone or intralesional calcification.

4. Zone of transition may be narrow or poorly defined.

5. The lesion frequently expands or breaks through the cortex.

Differential Diagnosis

1. Giant cell tumour of hyperparathyroidism

2. Non-ossifying fibroma

3. Aneurysmal bone cyst

4. Giant cell rich OSTEOSARCOMA.

(The most serious pitfall is to misdiagnose Osteosarcoma as Giant Cell Tumour. Remember that diagnosis of GCT in a teenager with open physis is very rare and the clinical diagnosis of Osteosarcoma should always be entertained first).

Histology

GCT is characterized by a large number of uniformly distributed osteoclast-like giant cells in a bland stroma with epithelioid spindle mononuclear cells.

Staging

CAMPANNACI STAGING (Rizolli, Italy)

I LATENT

II ACTIVE

III AGGRESSIVE

Stage 1

Benign, latent giant cell tumours.

These lesions are characterized by a static pattern of growth, without features of local aggressiveness.

Stage 2

Benign, active giant cell tumours.

These lesions are often clinically symptomatic.

Plain radiographs, bone scans, CT scans and MRI demonstrate expansile radiolucent lesions which frequently alter the contour of the cortical bone.

Stage 3

Aggressive giant cell tumours.

Symptomatic, rapidly growing lesions that are often associated with pathologic fractures.

Histologic sections show tumour infiltration of the tumour capsule with violation of the cortex and extension into the surrounding soft tissues.

Stage 3

Clinically the skin overlying the tumour often has ulcerated at the time of presentation.

Pulmonary Metastasis

1-2% of patients with GCT develop pulmonary metastases that are histologically identical to the primary tumour.

Aggressive lesions and recurrences were found to be risk factors for pulmonary metastases.

They can be solitary or few in number.

Resection of lung metastasis

Peripheral nodes can be resected thoracoscopically with excellent long-term survival.

Treatment

Treatment of giant cell tumour of bone is basically surgical.

The first decision to be made is whether to perform an intralesional excision (curettage) or 'en bloc' resection of the tumour.

Curretage

Extended curretage with bone grafting for Stage 1 and 2 GCT.

It involves the use of a large cortical window with no over hanging cortex.

The walls of the cavity was curreted with high speed burr.

The overall recurrence rate post extended curretage is estimated at 10 to 15 %.

Wide excision

Wide en-bloc resection with 1 cm cuff of normal tissue is the best option for Stage 3 GCT

Reconstruction Option

1. Allograft

2. Vascularized Fibula graft

3. Endoprosthesis

Allograft

Cadaveric obtained allograft is the main source for this type of reconstruction.

The allograft is fixed to the remaining bone either by intramedullary nailing or plating, supplemented by bone cement.

Fixation by plating is shown in the picture.

Vascularized Fibula Graft

A long segment of fibula can be resected together with its segmental blood supply.

Meticulous microsurgical technique for anastomosis of the vessel pedicles (artery + vein) would ensure the survival of the graft.

Vascularised graft enhances healing and provides almost total biological incorporation in long term follow up.

Osteomyocutaneous vascularised fibular graft is the best option to reconstruct distal radius.

Endoprosthesis

Endoprosthesis is the best option especially in the lower limb, especially tumours involving the hip or knee joint.

Endoprothesis reconstruction provide immediate stability and allow early mobilisation and weight bearing.

10-15 year survival is reported in about 70-75%

However it is very expensive and most of our patients could not afford it.

Shown in the picture is a patient who has undergone wide resection of the distal femur. It was reconstructed with endoprosthesis plus knee joint replacement.

Prognosis

Prognosis is favourable in patient with complete resection of pulmonary nodule or those who had received chemotherapy.

The overall outcome of treatment is good.

Case Study

32 year old gentleman presented with right upper leg pain for 6 months duration. The pain started insidiously and there was no associated trauma or febrile episode prior to the onset of pain. The pain was mechanical in nature, aggravated by weight bearing and relieved by rest. There was no episode of night pain.

He first noticed a swelling over the upper part of right leg 3 months after the onset of pain. The swelling was initially pea-sized and gradully increase in size over the past 3 months to the present size of a tennis ball.

The pain was more intense for the past 1 month than it was previously and it had significantly impaired his normal ambulation and activity of daily living. He stopped working as an odd job worker since a month ago.

There was no significant loss of appetite or loss of weight. No history of chest discomfort or decreased effort tolerance. He had no previous history of medical illness. No family history of malignancy.

As an odd job worker he earns RM 800.00 per month. He is married with 3 children and he is the sole bread-winner of his family.

Physical Examination

There is an obvious swelling of the proximal end of right leg. The swelling is bony hard, non-tender and non-mobile. It extends to the knee joint line but does not go beyond it. No overlying skin inflammation. Skin and subcutaneous tissue is free from the swelling.

Lateral view of right leg. There is fixed flexion deformity of 20º.

Full flexion of right knee

Plain X ray

AP View

There is presence of a radiolucent bone lesion over the proximal end of right tibia extending from the meta-diaphyseal region to the subchondral bone.

However there is no extension to the adjacent femur and fibula.

The lesion is eccentrically placed to the long axis of the bone.

The lesion is expansile with presence of multiple septation within it and a narrow zone of transition.

The cortex is eroded but no cortical breach noted.

There is no evidence of bone formation or periosteal reaction.

No significant soft tissue swelling noted.

Plain X ray

Lateral view

Expansile radiolucent bone lesion over the proximal end of right tibia extending from the anterior cortex to the posterior cortex of proximal tibia.

However there is no extension to into knee joint, adjacent femur and fibula.

The cortex is eroded but no cortical breach noted.

No significant soft tissue swelling noted.

Local Staging

MRI - T1 weighted image

There is an irregular eccentric and expansile heterogenous intensity mass seen in the epiphysis and diaphysis of the lateral condyle of right tibia.

MRI

T2 weighted image

The lesion enhanced peripherally post-IV gadolinium with central necrosis.

The tibial cortex is thinned-out and irregular with loss of continuity.

Laterally, extends out into the adjacent muscle compartment.

The lateral collateral ligament is also involved.

The bone marrow extension is 10cm distal to the tibial plateau

No extension into the knee joint space seen.

MR Angiogram

The popliteal and peroneal neurovascular bundle is intact.

Systemic Staging

CT Lung

No radiological evidence of lung metastasis in the pre Op CT scan.

Biopsy

Trucut Biopsy Report

The section of tissue shows mononuclear stromal cells intermixed with uniformly distributed osteoclast like giant cells.

The finding is consistent with Giant Cell Tumour of the proximal right tibia.

Diagnosis

The above finding is consistent with aggressive stage 3 GCT, without lung metastasis.

Surgery - Wide En-Bloc Resection Of Proximal Tibia

Incision made from lower 1/3 of right thigh extending to the middle 1/3 of right leg to gain adequate surgical exposure of the tumour mass and knee joint.

Patella Tendon

The patella tendon was incised to look for sign of tumour infiltration.

The picture shows a healthy patella tendon with no evidence of tumour infiltration.

It was preserved for later reconstruction of extensor mechanism.

Wide Resection + Knee Disarticulation

Wide resection done with 1 cm cuff of normal tissue.

Bone cut was done 5 cm distal to the most distal extension of the tumour (determined from MRI).

Knee disarticulation done sacrificing all the knee ligaments.

Tumour Resected

The arrow points to the popliteal artery which was carefully dissected and preserved.

Both the common peroneal nerve and tibial nerve was also preserved to ensure a functional limb post-op.

The Tumour

The resected tumour included a cuff of normal tissue (1cm).

Reconstruction

The bony defect and knee joint was reconstructed with a cemented endoprosthesis.

The patella tendon was reconstructed using large non-absorbable Mersilon suture which attached the tendon to endoprosthesis.

Gastrocnemius Rotational Flap

Gastrocnemius rotational flap was done to provide a thick soft tissue coverage over the endoprosthesis.

Extracortical bone bridge interface technique was used to encourage incorporation of the endoprosthesis.

Closure

The final soft tissue coverage enclosing the whole prosthesis is shown here.

Size 18 drain was inserted to drain out haematoma and reactive serous fluid.

After closure of skin, the limb was immobilized with knee brace.

Post Op Care

The patient should be made aware of the risk of local recurrence which is estimated at 5%.

Radiotherapy is not recommended due to concern of sarcomatous transformation.

Chemotherapy may be considered in cases of lung metastasis.

The patient would be follow up regularly, 3-4 monthly for the 1st 2 years, then 6 monthly subsequently.

The reasons for regular follow-up are:

1. To detect local recurrence.

2. To detect lung metastasis. (metastasis has occurred even up to 10 years post-op_

Conclusion

GCT is an unprecdictable tumour.

No definite biological or histological parameters can be used to determine the prognosis or aggressiveness of this lesion.

In our population, GCT is locally aggressive with a higher incidence of pulmonary metastases.

Stage 3 GCT is best managed with wide resection for better local control.

The overall outcome of treatment is good.

GCT Link List

Natural history of GCT

Natural History of Giant Cell Tumour of the Bone - By Dr. Wan Faisham

Aggressive GCT

Aggressive Giant Cell Tumour of the Bone - By Dr. Wan Faisham