Desmoplastic infantile gangliogliomas (DIGs) are rare supratentorial tumors that arise in infancy. Despite the large size of these lesions, the prognosis is generally considered favorable after gross-total resection (GTR); however, in incidental cases tumor progression has been described. The authors report on a child harboring a DIG with a high-grade primitive cell population and glial differentiation. The progressive clinical course was determined by this cell component in spite of GTR and adjuvant chemotherapy. The significance of the presence of a high-grade primitive tumor component in the context of DIG is discussed.