Fig. 1

The pathologic and radiologic imaging of Patient 1; a axial non-contrast CT 3-years preoperative, showing asymmetry of the posterior thalami; b axial T1-weighted contrast-enhanced MRI immediately preoperative showing enhancing mass lesion in the right posterior thalamus; c axial T1-weighted contrast-enhanced MRI 8 months postoperative showing resection of the lesion with no residual tumor d axial T1-weighted contrast-enhanced MRI 13 months postoperative showing recurrence of the lesion in the right posterior thalamus; e histological evaluation shows pilocytic astrocytoma with piloid loose areas and f dense areas with eosinophilic granular bodies (f, arrow). The tumor showed focally elevated Ki-67 up to 10 % (f, insert); The tumor was strongly positive for GFAP (g) and histone H3 K27M (h); i copy number analysis using Illumina 450 k Infinium array showed no large chromosomal gains or losses of focal amplifications in glioma associated genes (blue labels)