title: [A case report of chordoid glioma with unusual features: Immunohistochemical and molecular findings and differential diagnoses].
abstract: We report the case of a 63-year-old healthy patient who was admitted for surgery of a suprasellar tumor with extension to the optic chiasm responsible of visual disturbance. Histopathological examination revealed a tumoral proliferation composed of epithelioid cells without atypia arranged in cords in a mucinous matrix surrounded by some lymphocytic inflammatory infiltrates. On immunohistochemistry, the neoplastic cells strongly expressed GFAP and CD34, a weak expression of EMA, an expression of TTF1 without immunoreactivity for brachyury. Ki-67 labeling index was low around 1%. The diagnosis of chordoid glioma was made. Surprisingly, tumor cells expressed IDH1R132H but molecular analysis did not reveal any mutation of IDH1/2 genes. There was no expression of p53 but high overexpression of EGFR. Chordoid glioma is a rare and low-grade entity. The precise histogenesis remains debated. Our case is unusual because of the infiltration of the optic chiasm and because of the immunoexpression of IDH1R132H without underlying mutations of IDH1/2 genes.
authors.affiliation: Service d'anatomie et cytologie pathologiques, hôpital Lariboisière, AP-HP, 2, rue Ambroise-Paré, 75475 Paris, France. Electronic address: arnault.tauziedeespariat@gmail.com.
authors.forename: Arnault
authors.initials: A
authors.lastname: Tauziède-Espariat
authors.affiliation: Neurochirurgie, fondation Rothschild, Paris, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Robert
authors.affiliation: Oncologie moléculaire, hôpital Saint-Louis, 75010 Paris, France.
authors.forename: Patricia
authors.initials: P
authors.lastname: de Cremoux
authors.affiliation: Service d'anatomie et cytologie pathologiques, hôpital Lariboisière, AP-HP, 2, rue Ambroise-Paré, 75475 Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Polivka
mesh_terms: D002551:Cerebral Ventricle Neoplasms / Q000473:pathology*; D003937:Diagnosis, Differential; D005910:Glioma / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques
keywords: Chiasma optique; Chordoid glioma; Gliome chordoïde; IDH1R132H; Optic chiasm