Giant cell-rich osteosarcoma or giant cell reparative granuloma of the mandible?

Giant cell-rich osteosarcoma (GCRO) is a rare subtype of osteosarcoma, and no literature has reported occurrence in the mandible region up to now. In this article, we report a case of GCRO originating from the mandible in a 67-year-old woman who presented a history of painless mass located in the left side of the mandible after teeth extraction. The curettage biopsy histologic diagnosis is giant cell reparative granuloma before mandibulectomy surgery, but panoramic radiograph revealed an osteolytic lesion. The tumor was completely resected with segmental mandibulectomy and soft tissue with postoperative histologic diagnosis of GCRO. The free fibula osteomyocutaneous flap was performed to reconstruct the defect of the mandible and gingival mucosa. The patient received postoperative radiotherapy and chemotherapy. The 1-year follow-up situation is fine.