Chondrosarcoma

Robert C. Susil and Deborah A. Frassica

Background

Chondrosarcoma accounts for what % of primary bone tumors?

Chondrosarcoma accounts for ~30% of primary bone tumors (behind osteosarcoma and multiple myeloma).

Are chondrosarcomas typically high- or low-grade lesions?

Most chondrosarcomas (80%) are low- to intermediate-grade tumors with relatively low metastatic potential.

What 2 precursor lesions may give rise to chondrosarcoma?

Osteochondroma (a cartilage-capped bony projection arising on the external surface of a bone) or enchondroma (a common, benign cartilaginous tumor that develops in the medulla of bone) may undergo malignant transformation to form chondrosarcoma.

What is the predominant age range for chondrosarcoma?

Most chondrosarcomas present in middle-aged to older pts.

What are the most common locations for chondrosarcomas?

Most chondrosarcomas (~75%) arise in the proximal femur, pelvis, or proximal humerus.

What are 3 common characteristics of pain associated with chondrosarcoma?

Pain associated with chondrosarcoma is typically insidious, progressive, and worse at night.

Chondrosarcomas of the skull base typically arise from what structures?

While chondrosarcomas of the skull base may arise from the clivus, most originate laterally from the spheno-occipital junction or less commonly from the spheno-ethmoid complex.

What is the typical pattern of spread for chondrosarcoma of the skull base?

Chondrosarcomas of the skull base are locally aggressive and may expand, destroying bone and compressing adjacent tissues.

What other tumor may often be mistaken for chondrosarcoma at the skull base? How can they be distinguished histologically?

Chordoma (particularly the chondroid variant) may appear similar to chondrosarcoma. Unlike chordomas, chondrosarcomas do not express cytokeratin or epithelial membrane antigen.