Late Sequelae after Neuroblastoma-Associated Paraneoplastic Anti-Hu Syndrome in a 4-Year-Old Boy

Abstract

Anti-Hu syndrome is a rare autoantibody associated paraneoplastic disease of the central and peripheral nervous system resulting in a variety of neurological symptoms. In pediatric patients it is described in the context of (ganglio) neuroblastoma associated Opsoclonus-Myoclonus Syndrome (OMS) and other paraneoplastic syndromes. The timely diagnosis of paraneoplastic autoimmunity in childhood is hampered by its rarity as well as by the diversity of clinical symptoms that may occur. We report a 4-year-old boy with gastrointestinal disorder and neurological symptoms due to neuroblastomaassociated anti-Hu syndrome. The patient stabilized under a multimodal oncologic, immunosuppressive and antiepileptic treatment regimen. Treatment of neuroblastoma was individually modified and especially the specific anti- GD2 post-consolidation therapy was substituted by oral cyclophosphamide maintenance therapy in order not to aggravate autoimmune encephalitis. At the age of 8 years, the boy has been in ongoing complete oncologic remission for two years after end of relapse treatment. However, he suffers from neurologic symptoms like focal epilepsy and late sequelae of the oncologic disease. This case shows that treatment of paraneoplastic anti-Hu syndrome is challenging, encephalitis may persist long after oncologic remission and may lead to developmental delay and a variety of physical sequelae.