The diagnostic value of hyperostosis in midline subfrontal meningioma.

Roentgenologic analysis of 66 patients with proved midline subfrontal meningioma indicates a very high incidence of hyperostosis. A total of 63 patients (95%) showed varying degrees of hyperostosis involving the cribiform plate, planum sphenoidale, or tuberculum sellae (including the chiasmatic sulcus). The planum sphenoidale is the most common site of hyperostosis (59%). In 19 cases (29%), the region of hyperostosis did not correspond to the site of tumor attachment. Mild or localized hyperostosis may be apparent only on tomograms. Small "blistering" and "saw-tooth-like" osteoma formation are reliable early signs of midline subfrontal meningioma; conversely, midline subfrontal meningioma can be virtually ruled out if hyperostosis is absent.