A huge osteoblastoma with aneurysmal bone cyst in skull base.

We reported a case of a huge osteoblastoma in the skull base of a young girl who had developed blindness in her right eye 1 year prior to examination. CT showed a large expansile bony lesion with eggshell margin over the skull base. MR imaging showed mixed solid and cystic parts with multiple fluid-fluid levels in the lesion. The optic chiasma and bilateral optic nerves were severely compressed by the tumor.