Lipoma of the frontal bone.

A 32-year-old woman was involved in an automobile accident, during which she hit the left frontal region of her head. Skull fi lms revealed an asymptomatic lytic lesion in the general region of the trauma (figs. 1 A and 1 B) . There was no external evidence of this lesion on physical examination. Neurologic examination was unremarkable and a bone scan was normal. A CT scan showed a lowdensity lesion between the outer and inner tables of the skull without extension in either direction (fig. 1 C). The density of the lesion was -40 H. At surgery, a wide streak of yellow discoloration of the frontal bone was noted after elevation of the periosteum. This extended far beyond the confines of the lytic skull lesion and involved both the inner and outer tables . The dura was not involved. Upon microscopic exam i-