Cranial Hyperostosis

Hyperostosis of the skull associated with an underlying fibroblastoma has been reported in a good many instances. It is recognized that in a small number of cases of fibroblastoma of the meninges there is an accompanying cranial thickening, with the presence of tumor cells within the thickened bone. The mechanism involved in the production of hyperostosis is still unsettled, but the clinical fact remains that hyperostosis and a subjacent fibroblastoma are sometimes associated. That an extensive thickening of the cranium may result from a fibroblastoma lying on the skull has not as yet been recognized. It is for this reason that we record an unusual case in which there was a fibroblastoma lying on the skull, accompanied by a pronounced hyperostosis of the underlying bone. This is the first example of this sort of which we are aware. Trauma seemed to play a rôle in the formation of the tumor