A: Computed tomography shows a well-circumscribed heterogeneously enhancing, mixed cystic and solid mass centered in the right temporal lobe. B–D: Magnetic resonance imaging reveals hypo- to iso-intensity on T1-weighted image (B) with heterogeneous contrast enhancement of the solid component (C) and hyper-intensity on T2-weighted image (D). E and F: There is restricted diffusion associated with this mass, particularly at the level of the solidly enhancing components. A–H: The tumor is relatively well-circumscribed with a distinct boundary (A), and characterized by largely alternating gliomatous (B, with higher cellularity; C, positive GFAP immunostaining) and sarcomatous (B, with relatively less cellularity; D, positive reticulin staining), along with focally abundant giant cells (E, frequently multinucleated) and foci exhibiting primitive neuronal features including high cellularity with an increased nuclear-to-cytoplasmic ratio, cell wrapping (F, arrows), Homer-Wright rosettes (G, arrows), and focally positive synaptophysin immunostaining (H). I: The Ki-67 proliferation index is markedly high. Original magnification: ×40 (A–D), ×100 (E, H and I), ×200 (F and G). Scale bars: 100 μm (A–D), 50 μm (E, H and I), 20 μm (F and G). GFAP: glial fibrillary acidic protein.