Abstract
BACKGROUND/AIM: Giant cell tumor of the bone (GCTB) is a locally-aggressive, benign tumor that typically affects young adults between 20 and 40 years old. CASE REPORT: A 15-year-old female presented to a primary care physician with pain in the lateral aspect of the left knee and was referred to our department with a suspected bone tumor owing to radiographic findings of osteolysis of the proximal fibula. Computed tomography indicated osteolysis of the proximal fibula, and the bone cortex was thin and partially irregular. Magnetic resonance imaging indicated a mass in the same area, with hyperintense changes in both T1- and T2-weighted images. No biopsy was performed; however, bone tumor curettage and artificial bone grafting were performed. The final pathological examination indicated osteoclastic, multinucleated giant cells. No malignant findings were observed, and the patient was diagnosed with GCTB. No recurrence was observed one year after surgery. CONCLUSION: This case highlights the occurrence of GCTB in a young patient at an uncommon location. Oncologic surgeons should consider GCTB as a differential diagnosis when an image shows translucency of the proximal fibula, even if the patient is younger than the usual age of onset.