Thickening of the bony walls of the orbit was formerly classified as hyperostosis circumscripta, as described in Naito's atlas.1 On the basis of the knowledge of meningiomas following Cushing's2 investigations, a new interpretation of these bony changes arose and a new classification became necessary. In a recent personal communication Schüller3 stated:
In the past ten years, since Naito's book appeared, we have observed some cases where the x-ray diagnosis of osteoma or hyperostosis circumscripta had to be corrected for hyperostosis in meningioma. But there are certain reasons that we cannot abandon the group of circumscribed hyperostosis of the skull ; because on one side there are cases without progression which are clinically harmless, and on the other side the circumscribed hyperostosis is the beginning of leontiasis ossea, which gives a bad prognosis and is not operable.
Osteoma of the orbit is quite a different process, as these bony
KNAPP A. ORBITAL HYPEROSTOSISITS OCCURRENCE IN TWO CASES OF MENINGIOMA OF THE SKULL. Arch Ophthalmol. 1938;20(6):996–1005. doi:10.1001/archopht.1938.00850240110007