MPC-10 RECURRENT ASTROCYTOMA WITH SOMATIC IDH MOSAICISM: A CASE REPORT AND WARRANT FOR MOLECULAR DIAGNOSTICS

Abstract Introduction Acquisition of somatic mutations is essential for the development malignant tumors such as diffuse gliomas. Recent single-cell analyses have pointed out importance mosaicism in pathogenesis cancer. Here we report a case IDH (isocitrate dehydrogenase)-mutant astrocytoma that has relapsed after intensive chemoradiation with IDH1 R132H mutation. Clinical and Pathological Findings A 36-year-old male presented epileptic symptoms mass lesion right frontal lobe. needle biopsy demonstrated IDH-mutant (grade 2). At age 41, tumor was completely resected, cells were diffusely positive grade 4 morphology. Chemoradiotherapy (PAV + IMRT 60Gy/30fr) added, but contrast-enhanced lesions reappeared 5 months initial surgery. The re-excised specimen astrocytoma, number R132H-positive very small compared to total cells, suggesting mutations. Conclusion It imperative clarify induction mechanism significance cell cancer, molecular genetic assessment sequencing digital PCR would be necessary addition immunostaining accurate diagnoses brain tumors.