Bone Tumors
Clear Cell Chondrosarcoma

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James C. Wittig, MD
Sarcoma Surgeon
Orthopedic Oncologist

Malignant low to intermediate grade cartilage tumor
Comprised of neoplastic chondrocytes
          With abundant, clear cytoplasm
           Little intervening matrix
Foci of conventional chondrosarcoma may be present
Accounts for approximately 2% of all chondrosarcomas
Approximately 15% rate of metastases primarily to the lungs

Signs/Symptoms:
Pain and swelling
There may be interference with motion of adjacent joint
Often a long duration of symptoms

Prevalence:
~2% of all chondrosarcomas
2 to 1 male predilection

Age:
Adolescence to old age
Most common in third and fourth decades (20 years to 40 years of age)

Sites:
Epiphyses of long bones (rarely metaphysis or diaphysis)
Most commonly proximal femur, proximal humerus, distal femur, proximal tibia

Usually osteolytic, expansile epiphyseal lesion May have focal calcifications Often a sharp interface between tumor and surrounding bone      Sclerotic rim is uncommon Overlying cortex is usually thin, but intact Rarely an associated soft tissue component

MRI: Clear Cell Chondrosarcoma of Proximal Femur

Bone Scan: Intense Uptake in Clear Cell Chondrosarcoma of Proximal Femur

Fine Marginal                                              Calcified matrix                                          Purely Lytic
sclerosis

Usually red, soft and granular       Not similar in appearance to a         conventional chondrosarcoma Multiple cysts may be present Small areas of gray or white cartilage may be irregularly interspersed

MICROSCOPIC PATHOLOGY

Large clear cells with abundant cytoplasm, sharp cell border Highly cellular, uniform nuclei Nuclei are more pleomorphic than chondroblastoma (less uniform compared to chondroblastoma) Mitotic figures rare Focal calcifications may be present Sparse lobules of calcified chondroid matrix resemble grade I chondrosarcoma Scattered  reactive bony trabeculae Occasional multinucleated giant cells Special stains-               S-100- positive                  P.A.S-positive Heavy glycogen production accounts for the clear appearance of the cytoplasm May have small deposits of uncalcified or calcified osteoid

(Left arrow) Clear cell
(Right arrows)  Osteoid Production