Figure 1. Morphological and immunohistochemical characterization of the chordoma tumor giving rise to MUG-Chor1 cell line.

. A) Hematoxylin/eosin stained section show lobulated myxoid tumor tissue with cords, strands and nests of tumor cells with pale/eosinophilic to vacuolated cytoplasm. B, C) In detail, the tumor is composed of small cells with eosinophilic cytoplasm and partly spindle cell morphology and large vacuolated/physaliferous tumor cells including “signet ring” shaped cells. D) All cell phenotypes yield the chordoma-specific nuclear staining for brachyury. Arrowheads: small cells; asterisks: large vacuolated/physaliferous cells; arrows: “signet ring” cells. Scale bars: 500 µm (A), 50 µm (B, C); D: original magnification X20.