Turcot syndrome (TS) is a rare hereditary disorder clinically characterized by the occurrence of primary tumors of the colon and the central nervous system (CNS). Here we present the case of an 11-year-old boy with a synchronous clinical presentation of both glioblastoma multiforme (GBM) and colonic adenocarcinoma. A molecular genetic study revealed microsatellite instability in the DNA mismatch repair (MMR) gene. This patient ultimately survived for 13 months after clinical presentation. Based on this case study, the synchronous presentation of glioblastoma multiforme and adenocarcinoma of the colon might suggest a shorter survival rate for patients with Turcot syndrome. A literature review complements this paper.