Review Question - QID 220829

This patient is presenting with a giant cell tumor of the proximal fibula. En-bloc resection of the mass is reasonable given that attempted intralesional curettage would likely not be possible with the minimal remaining cortical bone (Answer 5).

Giant cell tumor (GCT) is a benign but aggressive bone lesion that most often occurs in adults aged 30-50. Around half of GCTs occur around the knee joint, but they can also occur in other locations, such as the upper extremity and spine. Radiographically, GCTs often present as an expansive, lytic lesion. If there is cortical disruption, they may also present with an associated soft tissue mass. The histology of GCTs demonstrates multinucleated giant cells with stromal cells that resemble fibroblasts. Of note, the neoplastic cells are the stromal cells, which stimulate the proliferation of the multinucleated giant cells. While GCT is a benign lesion, it is aggressive and can metastasize to the lungs. As a result, GCT is typically treated and not observed (Answer 4) when identified. Treatment can consist of intralesional extended curettage or wide resection with allograft or prosthetic reconstruction. Denosumab is an anti-resorptive medication that blocks osteoclastic activity and is typically reserved for unresectable tumors or as an adjuvant to surgery.

Yu et al. performed a retrospective cohort study of patients with GCT who underwent wide resection and mega-prosthesis reconstruction. They identified 19 patients with a mean follow-up time of 128.9 months. No patients developed recurrence or metastatic disease during the follow-up period. Prosthetic loosening was the most common complication, occurring in 31.6% of patients. The knee range of motion varied from 30 to 110 degrees of flexion. Six patients underwent revision surgery for loosening, infection, or periprosthetic fracture. The authors concluded that prosthetic reconstruction after en bloc resection is effective in minimizing the risk of recurrence of GCTs, and their results suggest satisfactory outcomes can be achieved despite a high rate of loosening over time.

Niu et al. performed a retrospective study of 621 patients with GCT followed for a mean of 49 months. Extended curettage was the most common surgery performed, and had an 8.6% rate of recurrence. In patients with recurrence, repeat curettage or wide resection was performed. Roughly 3.4% of patients developed pulmonary metastatic disease during the study period. The authors concluded that extended curettage provided good local control with a relatively low rate of recurrence.

Abdel et al. conducted a retrospective cohort study specifically focusing on proximal fibula tumors and their surgical outcomes. They included 120 patients with aggressive benign tumors of the proximal fibula, of which 19% were GCTs. A total of 56/120 (46%) patients underwent en bloc resection. Ten patients had recurrence of their lesion, 70% of which occurred with intralesional curettage. The authors concluded that en bloc resection of proximal fibula lesions may be preferred due to lower local recurrence when compared to intralesional curettage.

Figure A demonstrates an expansile, lytic lesion of the right proximal fibula.

Incorrect Answers:
Answer 1: Denosumab can be considered as an adjuvant to surgery, or in tumors that are in a location not favorable to resection. This patient’s lesion is in a location that is resectable.
Answer 2: Extended curettage is a very reasonable option. However, in this case, the lesion has occurred in the proximal fibula, which typically is amenable to en bloc resection. Extended curettage would be a better option if the lesion occurred in a more structurally important region, such as the proximal tibia or distal femur. Moreover, the paper by Abdel et al. recommends en bloc resection given the lower rate of recurrence when compared to curettage alone.
Answer 3: Radiofrequency ablation is not a viable option to treat these tumors
Answer 4: While GCTs are benign, they are aggressive and can metastasize. They should be treated rather than observed.