Multiple synovial osteochondral bodies are present within the popliteal fossa and anterior knee capsule. Image

Innumerable small nodules of chondromatosis Image

multiple yellow gray nodules resemble cobblestones Image

variable sizes and shapes of nodular hyaline cartilage surrounded by a synovial lining Image

synovial cells some with reactive changes and devoid of nuclei are present along the outer rim of the nodules Image

lobular proliferation of reactive chondroid cells without atypia; mild atypia is acceptable Image

Clonal changes have been identified suggestive of a true neoplastic process.