While the IDH1 mutation is separately detected in more than 80% of gliomas, 7–14% of cytogenetically normal AML, and 90% of enchondromatosis, with the most frequent mutation type represented by R132H [50,51], from our literature review, this last one is simultaneously present in enchondromas, brain gliomas, and acute myeloid leukemia in all cases where molecular analysis was performed, in detail, in the three cases of OD with BG, and in our case where all three diseases coexisted. Here, IDH1 is linked to brain glioma.