Progression of Cabozantinib-Related Osteonecrosis Mimicking Metastases on Bone Scan

Patient was a 73-year-old woman with metastatic renal cell carcinoma. Bone scan showed multifocal bone metastases. The patient received cabozantinib treatment for more than 1 year. On the follow-up bone scan, the previously biopsy-proven left pelvic bone lesion has improved, whereas the right maxillary lesion showed increased extent and intensity of abnormal radiotracer uptake. Given the different change pattern of these lesions, the right maxillary lesion was further evaluated. Biopsy results confirmed devitalized bone with bacterial colonies overgrowth and without tumor cell, suggestive of medication-related osteonecrosis.