Neurilemmoma

a benign tumour arising from a nerve sheath (typically from spinal nerve roots and the cervical, sympathetic, vagus, peroneal and ulnar nerves) or rarely from a bone (most commonly the mandible, sacrum, maxilla, femur and humerus). This tumour is also known as a benign schwannoma or neurinoma. Sometimes patients have pathologic fractures. The tumours in bone are composed of compact cellular regions (Antoni A areas) and loosely arranged hypocellular areas (Antoni B areas). On radiographs, neurilemmomas may take different forms:

central involvement, characterized by a focal osteolytic area with a sclerotic margin;

local involvement of a nutrient canal, producing a dumbbell lesion; or

periosteal involvement, with cortical erosion.