Dull ache increasing with motion is reported. Later osteal deformations occures. Child of 10 y.o. Cortical layer is thin and atrophic. Operation stage .
Visual field is full with huge amount of gian cells.
Giant cells contain dozens of nuclei and are mixed with small cells. Nuclei are usually center located. After operation X-ray. Osteal grafts are fixed . X-ray of the same patient 1 year later.