Giant cell tumour of bone
A demographic study from a tumour unit in South Africa
Keywords:giant cell tumour of bone, demography, benign tumour
INTRODUCTION: Giant cell tumour of bone (GCT) is a rare primary bone tumour. Little is known about the epidemiology of this tumour in South Africa as most demographic information is based on research from Asia, Europe and North America. This research aims to raise awareness and promote early recognition of these tumours. Materials and methods: A retrospective analysis was conducted of all patients with biopsy-confirmed GCTs that presented between January 2010 and December 2014. Information pertaining to patient demographics, tumour location, treatment and outcome was recorded and analysed.
RESULTS: Twenty-two patients were included in the study. The mean age of patients was 32.4 years (range 12-63), and a slight male predominance (1.2:1) was observed. Tumours were mainly located at the end of long bones (91%) with the distal femur and proximal tibia being most commonly affected (55%). Two patients (9%) were diagnosed with primary malignant giant cell tumours. We observed a higher rate of lung metastases (18%) than previously reported. The median tumour volume was significantly higher in patients who developed lung metastases (467.4 cm3 vs 137.8 cm3; p=0.03). Three of the patients with lung metastases were HIV-positive (odds ratio [OR] = 10.5, 95% confidence interval [CI] = 0.84-130.66, p=0.076). All patients were treated surgically with extended curettage, local adjuvant therapy, polymethyl methacrylate (PMMA) and internal fixation or en-bloc resection with prosthetic or osteochondral allograft replacement.
CONCLUSION: Giant cell tumours of bone are uncommon. Demographics from South Africa emulate international statistics. No recurrence of GCTs was observed in our cohort despite the relatively large tumours at time of presentation compared to international literature that report recurrence rates of approximately 2%. The incidence of metastases and primary malignant GCT was higher than in previous reports. The association of these findings with HIV infection warrants further investigation. Metastases appear to be associated with the size of the primary tumour.