Among 14 cases who had single lesion, 3 cases were located in crinial bone, 2 cases in acetabular bone, 3 cases in vertebral column, 1 case in rib and 5 cases in long bones of extremities.

• 单发者其中颅骨3例，髋臼2例，脊柱3例，肋骨1例，四肢长骨5例。