ABSTRACT
A giant cell tumor (GCT) is a benign but locally aggressive tumor usually present over the knee joint. Its etiology is unknown but some studies have shown that it appears due to overexpression in RANK/RANKL by neoplastic mononuclear stromal cells signaling pathway, which results in hyperproliferation of osteoclasts. This is a case of a 25-year-old male who presented with swelling associated with pain over his left distal femur since eight months. The range of motion (ROM) at the knee joint was painful from 0 to 110 degrees and no knee effusion was observed. Examination revealed a slightly mobile mass present over the knee joint. Additional preoperative workup such as Computed Tomography (CT) scan and Magnetic Resonance Imaging (MRI) was done. Histopathological findings showed the presence of large multinucleated osteoclast-like giant cells. Radiographs showed a permeative lytic lesion within the distal femur with surrounding cortical destruction. Surgical excision by curettage and bone grafting was done. The patient did well, without clinical recurrence at one-year follow-up. A local recurrence rate of 2.5 to 45% is observed. Aggressive operative excision, use of adjuvants at the time of resection, and ongoing postoperative monitoring can decrease patient morbidity.
