[Coexpression of intermediate filaments in notochords and chordomas and its significance in the histogenesis and diagnosis of chordoma].

Six chordomas, ten fetal notochords and eight adult notochords were stained for keratin, vimentin, GFAP, desmin, CEA, EMA and s-100 protein. Coexpression of four kinds of intermediate filaments was common in fetal notochords and chordomas. According to the histologic and immunohistochemical characteristics, chordoma may originate from the ectopic remnants of undegenerated notochord during the embryonic stage. The chordoma consists of two cell types; nonvacuolated and physaliphorous cells, and exhibits the potentiality of multidirectional differentiation. The coexpression of different types of intermediate filaments could explain the morphological transformation of chordoma.