This report describes a previously healthy toddler initially diagnosed with acute myelogenous leukemia with monocytic features and a bilateral thalamic high grade glioma at initial presentation. However, review of the outside hospital imaging favored bilateral thalamic infarcts with hemorrhagic conversion; the diagnosis of near diffuse cerebral venous sinus thrombosis (CSVT) with hemorrhagic conversion was confirmed with CT venography. He succumbed to uncontrollable intracranial pressure despite surgical decompression, medical management, anticoagulation, and chemotherapy. CSVT is the most common thrombotic complication present at diagnosis in AML and associated with high mortality, and diagnosis requires a high level of suspicion.