Atypical teratoid/rhabdoid tumor evolving from an optic pathway ganglioglioma: Case study

We report an atypical teratoid/rhabdoid tumor arising in a ganglioglioma from an 11-year-old male who had been treated over a nine-year period. A combined histologic, immunohistochemical, and molecular genetic analysis confirmed this diagnosis. Molecular genetic studies demonstrated a mutation in exon 9 of the INI1 gene in the tumor, which was not present in the patient's blood. This report is the first to describe progression of a ganglioglioma to atypical teratoid/rhabdoid tumor.