Background: Rasmussen's encephalitis (RE) is a form of chronic encephalitis presenting with intractable seizures and progressive neurological deficits in children. The occurrence of anaplastic ependymoma in a diagnosed case of RE has not been reported in the literature.
Case report: We report an eight and a half year-old boy, a diagnosed case of RE, suffering from intractable right-sided focal seizures, who developed features of raised intracranial pressure during follow-up. Repeat imaging revealed left fronto-temporoparietal mass for which near-total decompression was done. Histopathology of the mass revealed anaplastic ependymoma.
Conclusion: The etiology of such a co-existence or development of malignancy in a pre-existing RE is yet to be completely understood. Both these entities could have a common etiology of viral- or autoimmune-mediated process, but no definite conclusion can be drawn with all the literature available at the moment.