Hyperostosis frontalis interna associated with hypogonadism in an elderly man.

Hyperostosis frontalis interna (HFI), symmetric thickening of the inner table of the frontal bone, is relatively common in women but very rare in men. We report the case of an elderly male patient with HFI. This patient was accompanied by primary hypogonadism, which may be related to the underlying pathogenesis of HFI.