Giant Cell Tumor of the Occipital Bone and Secondary Aneurysmal Bone Cyst: Case Report and Review of Literature

Giant cell tumors (GCTs) and aneurysmal bone cysts (ABCs) are locally aggressive but benign lesions typically of the long bones of the extremities or spine and rarely involve the cranial vault or skull base. Although they are distinct entities pathologically and cytogenetically, GCTs can occur with secondary ABCs, which are likely reactive in nature. The reported cases have primarily involved bones of the extremities and, to our knowledge, there has been only one case of coexisting GCT and ABC of the calvarium or skull base. We describe a 27-year old woman who underwent complete resection of a GCT with secondary ABC of the left occipital bone and condyle. We discuss the significance of the co-occurrence of these lesions and their optimal management.