Exploring the Utility of FDG PET-CT in Metastatic Recurrent Extra Skeletal Renal Osteosarcoma

Metastatic renal osteosarcoma is a rare entity. We report a case of a 52-year-old male postright nephrectomy status presented to us with metastatic renal osteosarcoma. 18-fluorine- fluorodeoxyglucose (¹⁸F-FDG) avid lesions were seen in the right renal bed with extension to adjacent hepatic parenchyma. The patient exhibited a favorable response to 6 cycles of carboplatin and doxorubicin with no FDG avid lesions in the postchemotherapy follow-up scan. On 6-month follow-up scan, scan findings reveal a recurrent lesion at the renal bed region infiltrating psoas muscle and liver metastatic lesion. This case highlights the use of ¹⁸F-FDG positron emission tomography/computed tomography in metastatic recurrent extraskeletal osteosarcoma.