====== Hyperostosis frontalis interna ======

[[Hyperostosis frontalis interna]] (HFI) is a benign irregular nodular thickening of the inner table of the [[frontal bone]] that is almost always bilateral. The midline is spared at the insertion of the [[falx]]. Unilateral cases have been reported, and in these cases, one must R/O other etiologies such as [[meningioma]], calcified [[epidural hematoma]], [[osteoma]], [[fibrous dysplasia]], an epidural fibrous tumor, or [[Paget’s disease]].
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Tumor-associated hyperostosis is usually restricted to a small area immediately over the tumor, while the latter condition, HFI, can affect the inner table of the entire frontal region. HFI is a condition defined by bone deposition and thickening, usually limited to the inner table of the frontal bone, often sparing the midline. It has a prevalence of 5%-12%, more often affects women than men, and appears to be associated with elderly postmenopausal women in particular, with an incidence of 40%-60%
((She R, Szakacs J. Hyperostosis frontalis interna: case report and review of literature. Ann Clin Lab Sci. 2004 Spring;34(2):206-8. PMID: 15228235.))