Tissue removed from the second craniotomy. (a) The tumor is a densely cellular lesion composed mostly of small cells with small cell bodies (H&E, original magnification 200x). (b) A GFAP immunostain marks scattered single cells representing entrapped reactive astrocytes, 600x. (c) A Synaptophysin immunostain labels the cytoplasm of multiple tumor cells, surrounding their centrally-located nuclei (600x). (d) A neurofilament protein immunostain also labels the cytoplasm of many tumor cells as well as some processes from them (400x). (e) A Neu-N immunostain distinctly labels the nuclei of many tumor cells (600x).
