The specimen consists of a circle of dura from which is arising a bossellated tumour which appears
circumscribed on its outer surface but appears to be infiltrating and extending through the dura.
This patient presented at the age of 49 with a hard painless lump on the forehead near
the midline and straddling the hairline; this lump had been slowly increasing in size. Examined
showed a firm symmetrically rounded lump in the forehead some 8 cm in diameter, raised 2 cm
above the general contour of the scalp. The superficial temporal arteries were very large. A skull
x-ray showed erosion and proliferation of bone. At operation both bone and dura were infiltrated
by the lesion.