Cancer and Autoimmunity: Paraneoplastic Neurological Disorders Associated With Neuroblastic Tumors.

Cancer and autoimmunity come together in paraneoplastic syndromes (PNS), which reflect the remote, not direct, effects of cancer. In the pediatric population, a variety of PNS have been described, but the most common of these rare disorders are instigated by neuroblastic tumors, such as neuroblastoma, ganglioneuroblastoma, and ganglioneuroma. The main pediatric-onset neurological PNS are ROHHAD syndrome, anti-ANNA1 (anti-Hu), and opsoclonus-myoclonus syndrome. They manifest distinctive neurological features, which aid the diagnosis, though under-recognition still poses serious challenges and risks. In each clinical syndrome, a large subgroup of patients had no demonstrated tumor. Most neurological PNS are immunologically mediated, and CSF neuroimmunological studies show common elements of immune involvement in PNS as well as important differences. Future immunotherapy strategies may be able to take advantage of these abnormalities.