Fig. 1.

Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a glial neoplasm associated with a history of epilepsy in young people, diffuse growth patterns, frequent presence of oligodendroglioma-like components, calcification, CD34 immunoreactivity, and MAPK pathway-activating genetic abnormalities. (A) Common oligodendroglioma-like appearance (H&E, ×200), but (B) histological appearances can vary greatly within tumors (H&E, ×400). (C) CD34 immunostaining is typically strong and diffuse in the tumor (×100); and (D) is often found in the peritumoral cortex (×200).