Clinical and histopathologic features of chordomas in children and young adults.

Chordoma is a tumor of the axial skeleton that is distinctly uncommon in children and adolescents. Previous observations have suggested that chordomas in pediatric patients differ from adult chordomas in presentation, morphology, and behavior. This study examines the clinical and histologic features of chordomas in young patients (< or =25 years old). All cases from the Mayo Clinic files were graphed according to age and a bimodal distribution was observed. The 35 cases representing the youngest population were selected for review. Histopathology ranged from low cellularity tumors with lobulated architecture and abundant myxoid matrix (conventional chordoma), to those with varying amounts of chondroid matrix (chondroid chordoma), to more cellular tumors (atypical chordoma), and finally to neoplasms with high-grade spindle-cell differentiation (dedifferentiated chordoma). Over an average follow-up period of 129 months (range 1 to 501 months), there were 13 deaths (37%) and 3 patients with metastasis. This survival rate was slightly better than the reported mortality rate for adults with chordoma, but there was a subset of young patients (those with atypical chordoma) that had a significantly worse survival rate, suggesting that histologic subtyping may be predictive of prognosis.