Sections show a pilocytic glial neoplasm with sparse Rosenthal fibers and more frequent eosinophilic granular bodies. There is also a significant component of large dysmorphic cells, some of which have nuclei and cytoplasm consistent with neuronal morphology. Many of these cells are immunoreactive for synaptophysin, either on the cell surface in a particulate pattern or diffusely in the cytoplasm. A few of the synaptophysin positive cells are clearly binucleate, Neu-N reactivity is sparse to negative, and has a granular pattern in the cytoplasm of a few of the large cells, but not in the nuclei. There is extensive reactivity of the intervening matrix for both synaptophysin and GFAP. Pilocytic areas are strongly GFAP positive, and some large cells are also variably reactive for GFAP. Focal areas have extensive branching vessels with with a significant connective tissue adventitia, seen by Masson and reticulin stains. These features place this neoplasm is the category of a low-grade ganglioglioma.