Giant cell tumor of bone: imaging and histology changes after denosumab treatment

Excerpt

We read with interest the article “Giant cell tumor of the bone: aggressive case initially treated with denosumab and intralesional surgery” by Dr von Borstel et al. [1]. The authors describe a patient with a giant cell tumor of bone (GCT) who was treated with denosumab, developed interval changes noted on imaging studies and biopsies, underwent “intralesional treatment,” and apparently developed recurrence. Approximately 7 weeks after denosumab was started, an MRI was interpreted as “suspicious for worsening disease with increased intralesional heterogeneity, perilesional fluid-like signal, and circumferential cortical/periosteal thickening and irregularity.” The authors emphasize that the MRI was misinterpreted, and that the lesion was responding appropriately to denosumab. Curettage 3 weeks later showed “no evidence of giant cell tumor” and “absence of proliferating giant cells and mononuclear cells,” supporting a reactive lesion. The authors subsequently argue that the post-denosumab samples were “negative for tumor cells,” although the lesion subsequently recurred. …