Tumors of the Skull Base

Rare tumor: 0.2% of all intracranial tumors; 3% to 4% of all primary malignant bone tumors

Average age: 41 years (range: 7 to 78 years)

3:2 male/female ratio for skull base chordoma

25% to 35% of chordomas arise in the central skull base (clivus)

50% arise in sacrococcygeal location with a minority of tumors arising in spinal column

65% of skull base chordomas arise in the sellar or parasellar regions

Intracranial tumors typically present with headache, visual disturbances (diplopia), pituitary dysfunction, and symptoms secondary to increased intracranial pressure

Tumor is locally aggressive: invades skull base and destabilizes the skull

Survival at 5 years is estimated at 50%

Treatment is surgical resection and targeted radiation such as proton beam therapy

Iso- to hypointense lesion on T1-weighted image and hyperintense on T2-weighted image

Often shows bone invasion and sometimes soft tissue involvement