Fig. 3
Representative patient treated with reirradiation and temozolomide (ReRT/TMZ) showing the usefulness of IDH1/2 mutational status evaluation in establishing the RIG diagnosis (Case 9). A T2-weighted magnetic resonance image at the initial presentation showing a hyperintense lesion in the left medial frontal lobe (black arrow). B T1-weighted magnetic resonance image with gadolinium enhancement obtained 17Â years after the primary tumor showing a contrast-enhanced lesion just posterior to the primary tumor, which was included within the prior radiation field. C Sanger sequencing analysis of the secondary tumor (glioblastoma) showing the homozygous G nucleotide at codon 515 of the IDH2 gene, indicating the IDH2 gene was wild-type. D Sanger sequencing analysis of the primary tumor (diffuse astrocytoma) showing the heterozygous G and A nucleotides at codon 515 of the IDH2 alleles, indicating the IDH2 gene was mutant. E T1-weighted magnetic resonance images with gadolinium enhancement were obtained 23.0Â months after the secondary tumor diagnosis showing a distant recurrence in the cerebellum (white arrow)