A chondrosarcoma is a malignant tumor found at the petro-occipital synchondrosis, the joint between the clivus and the petrous bone of the skull.

Etiology for Chondrosarcoma

Chondrosarcoma arises from cartilaginous elements within the petro-occipital synchondrosis.  A tumor arises when the cartilaginous elements mutate and begin to grow abnormally. The reason for growth is unclear.