Methylation profiling of the glial component of the recurrence matched with high confidence to methylation class astrocytoma, IDH-mutant, low-grade (0.99); however, the sarcoma matched with high confidence to the MC oligosarcoma, IDH-mutant, with a final confidence score of 0.90. The gene discussed is IDH1; the disease is astrocytoma (excluding glioblastoma).