Disseminated Adult Atypical Teratoid Rhabdoid Tumor causing Dorsal Midbrain Syndrome

A 36-year-old woman with no significant past medical history presented with 1 month of severe headaches and vomiting associated with abnormal eye movements. MRI demonstrated an enhancing mass along the splenium of the corpus callosum and in the pineal region extending towards the right thalamus with a necrotic center. Her vision was 20/25 OU, and pupils were round and slowly reactive to light without relative afferent pupillary defect. Extraocular movements revealed -4 upgaze deficits bilaterally, partially overcome by oculocephalic maneuvering. Convergence retraction nystagmus and light-near dissociation were present. Dilated fundus exam was unremarkable OU.