Giant cell-rich osteosarcoma(GCRO)is a special subtype of osteosarcoma,and is rare.This paper reported the clinical and imaging data of the patient with GCRO who had special imaging manifestations,and to provide the reference for clinical diagnosis and treatment of GCRO.The patient,a 69-year-old female,was admitted to the hospital due to the discovery of a mass in the right lower leg for 1 month.The X-ray imaging manifestations showed that the cortical bones on the opposite edges of the tibia and fibula presented mild moth-eaten changes.The plain CT scan imaging manifestations showed that there was a mass within the muscle,and the cortical bones on the opposite edges of the tibia and fibula were destroyed.The tumor only involved the superficial cortical bones and did not invade the deep cortical bones and the medullary cavity.The MRI imaging manifestations showed that the local bones of the tibia and fibula adjacent to the tumor were destroyed,and the medullary cavity was not invaded.An extended resection of the mass was performed,and the postoperative pathological diagnosis was GCRO.The patient received chemotherapy after the operation.However,a tumor in the right lower leg recurred 15 months after the operation.The patient passed away 21 months after the operation.Giant cell-rich osteosarcoma often leads to misdiagnosis or missed diagnosis due to its non-specific clinical manifestations.This paper explored the clinical manifestations and imaging data of the patient with GCRO in order to improve the clinical understanding level and the level of diagnosis and treatment of the clinicians about this disease.