The X ray film of benign rib tumours showed expansive bone destruction, whose border was distinct and whose cortex of bone was intact.

Osteoid osteomas usually occur in the axial skeleton (especially tibia and femur) in bone cortex of young males in the second decade of life.

Closer examination of the layer of new bone deposited on the cortex of the allograft shows a number of histologic features previously thought never to occur in allografts.