FIG 1. Histopathology of the invasive edge of the glioblastoma multiforme from patient 12 in the Table.

Top left, A, Low power, x50, hematoxylin and eosin stain depicting tumor core (TC) and brain adjacent to tumor (BAT). Note the high cellularity of the core in the white matter, with invading cells spreading as far as the leptomeningeal space (LMS).

Top right, B, High power, x400, of the BAT emphasizing perineuronal satellitosis—glioma cells around neuronal cell bodies (arrows).

Bottom left, C, Medium power, x100, with a monoclonal antibody (NeuN) staining neurons.

Bottom right, D, High power, x400, view of C highlighting immunoreactive neurons (arrows) surrounded by infiltrating tumor cells. These vacuolated neurons appear unhealthy, and therefore, are likely to contain less NAA. A healthy neuron is indicated for comparison (arrowhead).