Fig. 2.

a A fibrocartilagenous cap with an atypical proliferation of variably mineralized and calcified bony trabeculae (“blue bone”). Note the atypical interface between the cartilage cap and bony proliferation (hematoxylin-eosin, original magnification ×25). b Higher magnification of image 2A focusing on the area of interface (hematoxylin-eosin, original magnification ×100). c High magnification of cartilaginous zone with numerous atypical pleomorphic chondrocytes (hematoxylin-eosin, original magnification ×200). d Illustrates a highly vascular connective tissue, scattered inflammatory cells, fibroblasts, and occasional osteoclasts (hematoxylin-eosin, original magnification ×100)