Giant cell tumor of ribs masking a huge soft tissue tumor: A potential diagnostic pitfall

Apart from the typical lesion with giant cell tumor evenly distributed among the mononuclear cells, there are secondary change including multiple hemorrhage cyst formation, irregular ossification and spindle cell proliferation, which mimics malignancies. H3.3 p.G34W immunohistochemistry and H3F3A mutation detected by Sanger sequencing supported the diagnosis of giant cell tumor. Our studies emphasized radiological and histological polymorphism and the diagnostic value H3F3A mutation, with a review of other published reports to assess radiological and pathological diagnosis and outcomes in case of misdiagnosis and overtreatment.