A New Sarcoma Shortly after Treatment for High-Grade Glioma with Adjuvant Chemoradiation: A Case Report.

Introduction:High-grade gliomas are central nervous system tumors conventionally treated with surgery followed by adjuvant chemoradiotherapy. Secondary cancer due to radiation therapy is a rare yet established phenomenon that typically occurs years after radiation therapy. Case Presentation:In this case, we discuss an early presentation of a second cancer adjacent to the radiation field. This case report is of a 52-year-old male who developed a new scalp sarcoma at the site of primary surgery 8 months after radiation therapy. Genetic testing revealed a heterozygous missense variant in the NF1 gene, a variant of uncertain significance. The report highlights that this case does not conform to the expected criteria for postradiation sarcoma in terms of timing. Conclusion:Secondary cancers may arise earlier than expected, even in phenotypically normal patients, as they may have unmanifested variants of relevant mutations. The question of pre-radiotherapy screening for radiosensitivity syndromes and diseases requires further study, as current data are limited and do not provide enough insight into the significance of different genetic variants.