Epithelial and pseudoepithelial differentiation in glioblastoma and gliosarcoma

BACKGROUND. Glioblastomas exhibit a remarkable tendency toward morphologic diversity. Although rare, pseudoepithelial components (adenoid or epithelioid) or true epithelial differentiation may occur, posing a significant diagnostic challenge. METHODS. Hematoxylin and eosin–stained slides were reviewed, and immunohistochemistry and fluorescence in situ hybridization were performed. RESULTS. The patients included 38 men and 20 women. The median...