Tyrosine kinase receptor expression in chordomas: phosphorylated AKT correlates inversely with outcome.

Chordomas are rare neoplasms arising from notochord remnants. Tyrosine kinase receptors (RTK) are altered in these lesions. We used a tissue microarray containing 58 chordomas to examine the expression of platelet-derived growth factor receptor (PDGFR)-α and PDGFR-β, epidermal growth factor receptor (EGFR), c-Met, c-Kit, pAKT, mammalian target of rapamycin, and HER2 by immunohistochemistry and fluorescence in situ hybridization.