Hyperostosis Frontalis Interna

Cortical thickening confined to inner table of the skull noted as an incidental finding.
May be flat and smooth or irregular.
Primarily affect frontal region, may extend in parietal regions.
Bilateral and symmetrical involvement.
Relatively spares midline, at the sagittal suture.
Best seen on CT.

Commonly seen in post-menopausal females , over 50s.
Unknown etiology , presence in post-menopausal women suggest possible hormonal influence.
Clinical significance - None.