Recurrent ependymoma with cartilaginous metaplasia in an adult: report of a rare case and review of literature.

Cartilaginous metaplasia in ependymomas is an uncommon phenomenon and is hypothesized to be due to metaplasia of the mesenchymal supportive elements or arising from the neoplastic glial cells. Most of the previous cases reported have occurred in children less than 10 years of age. The present report discusses an unusual case of ependymoma with cartilaginous metaplasia in a 21-year-old male. A brief review on the histogenesis of cartilaginous metaplasia is also provided.