XRay shows subtle cortincally-bsed lesion in the lateral cortical margin of the proximal tibial diaphysis. There is a small area of periosteal uplifting in the lateral aspect of the proximal distal tibia diaphsys as well. No soft tissue component is seen. This sutble lesion within or adjacent to this region with some periosteoal uplifting is compatible with juxtacortical chondroma Image

emenating from bone Image

mostly looks like this Image

some more chondromyxoid foci Image

more cellular area Image

Juxtacortical (periosteal) chondromas are a variant of enchondromas that arise from the periosteum. Thus, they