Pathology: poorly differentiated chordoma

Poorly differentiated chordoma

• Lobulated; sheets of epithelioid-rhabdoid-polygonal cells

• Eosinophilic cytoplasm with rare vacuolation

• Hyperchromatic round-ovoid nuclei with mild-moderate pleomorphism; rare mitotic activity

• Focal myxoid stroma

• IHC: INI1