Fig. 3.

A, B Microscopic examination of the resected tissue showing spindle-shaped or star-shaped cells with irregularly enlarged nuclei, some of which show unnatural formation of osteoid and cartilage tissue. A Low-power view of hematoxylin- and eosin-stained section. B High-power view of hematoxylin- and eosin-stained section. C Expression of Ki-67 analyzed by immunostaining. The labeling index was 30%. D Expression of p53 analyzed by immunostaining, showing diffuse positive images beyond the range of Ki-67 positivity